The Birthday Favour

The Birthday Favour

Thanks go to Little_Sister and tangentjoker for helping me edit this story.
Any mistakes that remain are my own. [MyGuiltySecret]

It was the morning of May 19th, my brother's birthday. He was 20 and at university. I was 18 and studying for my A-levels. We both still lived at home; him because the rent in London is so expensive, and me because I'm still in school.

Neither of us realised it on that bright Thursday morning, but he was going to get a birthday present he would never forget.

I knocked on the door to his bedroom.

"Yeah?" My brother's voice sounded distracted, as if he was in the middle of something.

I went in. I saw him dropping a towel into his sport bag, glimpsed shorts and T-shirt under it.

"Happy birthday, big brother." He turned to face me and I handed him the envelope.

He smiled as he took it from me. "Thanks, sis." He tore open the envelope. "You shouldn't have," he said as he took the card out. It was just a cheap card, bought from the corner shop, so I didn't blame him for sounding a little disappointed. I couldn't help it. I was just a student and I didn't have a lot of money. Still, I hoped he would be pleased with what he found inside it.

He opened the card and found my real present to him. I may not have much actual cash, but I can be inventive.

He took out the token I'd put inside it, examining it.

If you added up all the hours I'd spent on it, it must have taken me a good few days to make. I'd done everything I could to make it look like an actual banknote, something valuable.

I'd gone to the trouble of hand-making the paper, so it wouldn't just feel like something that had been pulled out of a photocopier. I'd used the finest Rotring pen I could find, and drawn lots of tiny, thin lines to look like engraving on the background. I'd done a watercolour wash across it, so the background shaded from green to blue. The foreground had a picture of a present on it, done in acrylics to really make it stand out, the pale blue ribbon on it as detailed as I could get it. The big bow atop it had light and shade and highlights all delicately painted in. At the top left it said, in elegant calligraphy:

"I promise to pay the bearer

ONE FAVOUR"

The capital letters on the second line were big bold copperplate, done with a technique called impasto - I'd used enough paint to actually give them some depth. At the bottom right I had signed it, big and swoopy and exaggerated, and underneath it was written something like a job title in much smaller letters, so it looked like something on a note that could have been issued by a real bank:

"Angie

YOUR LITTLE SISTER"

And where real notes nowadays had a copyright notice, I'd written in smaller letters, running vertically up the right hand side:

HAPPY 20th BIRTHDAY JACK, WITH LOVE FROM YOUR KID SISTER

It even had a serial number - today's date.

"Wow," he said, almost speechless. As he admired my handiwork, I rushed to fill in the silence.

"Just like it says, I'm giving you a favour for your birthday. Completely unrestricted. It can be as big as you want, or as small as you want. You can use it right now, or save it for twenty years. You can hold onto it until you're married with three kids and need a babysitter, or just send me round the corner to get you a pizza one night when you just can't be bothered."

"Anything?" he asked, smiling.

"Well, almost anything. I don't have much cash, remember, so anything that costs money is probably out. But other than that... yeah, anything."

"Even help me tidy up this pigsty?"

I looked around at his room. It was a state. Books everywhere. Huge thick textbooks, the science fiction paperbacks he loved reading so much. Binders with notes spilling out of them. Letters from the bank about his student loan. Discarded flyers about one event or another. Magazines about football. Dirty clothes and dirty dishes that hadn't made their way downstairs by themselves. Sweaty sports kit that needed a wash, and football boots that he hadn't even scraped the mud off yet. Things festering. A couple of mugs growing mould. The computer on his desk was barely visible because of the piles of stuff around it.

"Um... I wasn't thinking of such a big job, but yeah. If you want."

"Nah, don't worry, I wouldn't ask you to do that. There's some stuff in here I probably wouldn't want you finding, anyway."

"What, like those old porn mags under your bed? I found them ages ago. Yeah, I know you figured out how to get smut on your phone, but those pornographic magazines are still there, right?

"How did you...? Never mind. Anyway, there's other stuff. Personal stuff."

"Like what? Have you been stealing my panties or something?"

"No! Of course not!"

He denied it, but only after a hesitation. And was he blushing? Oh my god. Had my brother been stealing my underwear?

He stepped closer to me. Looking me right in the eyes, his eyes green like my own, so close that I could see the little light and dark flecks in the iris, the pupils as black as my hair. He continued talking, his voice lower and quieter now. Conspiratorial, as if we were sharing a secret.

"What if I asked you for some other kind of services? What if I asked you to set me up with one of those hot school friends of yours? Holly has a particularly fine figure, if I recall."

"Well... I... I'd..." I stuttered, taken aback by this turn of events.

His voice had dropped even lower now, barely even a whisper. If he hadn't been so close to me I doubt I'd even have heard it.

"Or what if I wanted a favour from you? A sexual favour? What if..." he was whispering in my ear now. "What if I asked you to suck me off? A blowjob from my sexy little sister?"

I felt my face redden. If I was surprised before, I was utterly shocked now.

"But... Jack! I... No. I couldn't! I'm your sister. I couldn't..."

He had pulled away and was laughing.

"I'm just messing with you! Don't worry, sis, I won't ask you for that. I was just kidding."

"Jack! You pig! How could you?"

"I really had you going there, didn't I? You should have seen your face!"

He was still laughing. I was tempted to take that token that I had worked so hard on right out of his hands and rip it up, there and then. But I didn't. It was his still birthday, and he was still my brother.

* * *

The day continued as normal. At least as normal as one this close to my exams could be. I went in to school and filled the day with structured revision. I buried myself in my notes and folders. I swotted in the library, desperately trying to cram in all the facts I could, testing myself, quizzing my friends.

Despite it all, I kept finding myself distracted. Questions that had nothing to do with the subjects I was studying kept intruding into my consciousness.

Would I have done what he asked? If he had really asked me to suck him off, would I have taken his dick in my mouth, bobbing my head up and down until he came?

Did he mean it when he called me sexy? Did he really think of me like that? I felt the warmth inside me as I considered him thinking about me, fantasising about me. Despite the fact I was sitting at a table with Holly, Lucy and Amanda, I found myself rubbing my thighs together under the table, wiggling a little in my seat.

"Angie?"

Holly's voice called me back to what I was supposed to be doing.

"Um... yeah?"

"Well, you're never going to pass any exams with that level of concentration," she said, exasperated. "I asked you a question. You know, one from the past papers we're looking at?"

"Yeah. Look, I can't concentrate today." I paused. "Fuck it, I'm going home. Seeya tomorrow."

I slipped the orange sheets full of questions from previous exams back into the buff-coloured file I stored them in. I scooped up my books and folders from the smooth surface of the table, and dumped them all in my bag. As I walked towards the big, glass doors of the library, I heard my friends muttering to each other behind me, but I didn't care. One or two of the other students using the library looked up, but most were far too intent on what they were doing to spare me any attention.

As I stepped outside the building itself, I paused for a moment. The area of the school by the library had large plate glass windows, and I looked at my reflection in them. Was he right? Was I really sexy? I pretended to look through the windows at the typed sheets of A4 on the noticeboards, but I was really concentrating on my reflected image. My hair was long, dark and almost jet black; its straightness falling to the upper slopes of my breasts. The eyes looking back at me were a bright, emerald green. My skin was creamy, and at least at the moment, unblemished by spots. Was my nose a tiny bit too long, my lips that little bit too full to be beautiful? I looked at my body, looking past the blue blazer with a badge on the pocket, the unflattering grey pleated skirt falling to just above my knees and the tie with those diagonal blue and grey stripes. I examined my figure. I was slender without being skinny, and I knew that I had just a couple of pounds of puppy fat that I hadn't managed to shift. And breasts. Yes, I had breasts. But were 34C big enough to be attractive to an older man? A man like my big brother? Didn't men tend to like big breasts?

And had he really stolen my panties? Or was he just surprised that I thought he might? If he had stolen them, what did he do with them? Did he sniff the crotch while he jerked himself off, smelling the scent of my pussy as he came? Or did he wrap them around his prick while masturbating, shooting his cum into them as he orgasmed?

I thought about his penis. I hadn't actually seen it for years. The last time was on a beach while he was changing into his swimming trunks. That must have been over a decade ago now. He wasn't very developed then, so when that towel slipped what I had seen had been tiny.

I bet he wasn't tiny now. I found myself thinking about my brother's cock. A 20-year-old's cock would be big. Especially if he had an erection..

When had I got so perverted? One little joke from my big brother and I...

No. I had to stop thinking about it.

That day on the beach, he'd been just a skinny little kid. One who liked football and cartoons and teasing his younger sister. But he wasn't a kid now. He'd grown up. He was a grown man. And that meant every part of his body would be an adult's.

I found myself picturing my brother's cock again, how big it would be, what it would look like while he... No, stop it. I had to stop this.

But I couldn't.

It was wrong, and I was bad. So bad. But I couldn't deny that thinking about my brother was turning me on. Thinking about my own brother's cock was making me wet. I felt the heat in my belly and the moistness that I just knew was soaking my panties. Shit, if it carried on like this I'd end up failing my exams and flipping burgers for a living. But there was no way in hell I could concentrate while I was so distracted by these deviant thoughts about Jack.

Yeah. I was doing the right thing getting out of here. I went home.

* * *

The house was empty at this time of day. Mum and Dad were at work, and Jack would either be at a lab session with his geeky fellow students or possibly at the gym for an hour or two. Whatever he was doing, I had the whole house to myself. I dumped my rucksack in the kitchen and headed straight up to my room.

I took my school blazer off, throwing it on a chair before I started dancing slowly around the room. I giggled to myself like a schoolgirl (which I technically was, of course, even if I was in the 6th form).

I slowly undid my tie, imagining I was stripping. Doing a striptease for... hell, doing it for my older brother. I undid the knot, pulled either end, sawing it backwards and forwards before pulling it off and throwing it across the room. I imagined Jack watching me, his eyes the colour of jade staring openly at me as I slowly undid the buttons on my blouse, taking my time. I slid one shoulder out of it, then the other, before letting it drop to the floor. I turned around, so he could see me undo my bra. It was just a cotton bra, practical and comfy but not very sexy. In my imagination, it was silk and lace and a lot sexier. I was getting wetter as I imagined how hard he would be staring at my body, how stiff his cock would be. I wasn't just damp, I was soaked as I imagined his panting breaths as he saw what I was doing. I turned around, let the straps of the bra drop, before throwing it at my imaginary brother. Now he had his dick out, and was openly stroking it.

I had no idea what his cock actually looked like in real life, but in my imagination it was magnificent. I was too turned on to carry on with the game for much longer. I dropped my skirt and sopping panties to the floor, kicked off my shoes, ripped my long socks off. Naked now, I threw myself onto my bed.

I ran my fingers up and down my labia, puffy with desire, imagining they were Jack's tongue and that the wetness wasn't just my own juices but his saliva.

I realised what I was doing and tried to banish the image of my brother. I attempted to summon up some other fantasies. I tried to call to mind one or two of the hotter teachers I had imagined fucking, a boy in my year, even some movie stars I had masturbated to in the past. But the figure of my brother kept intruding. In the end, I just went with it. It was just a fantasy, right? A dirty, nasty sexual fantasy of my naked brother with his head in between my legs. In my mind, his tongue was sucking and lapping at my clit in time with the motions of my fingers rubbing it and circling it in the real world.

"Yes Jack. Oh yes. Just like that," I whispered.

I lifted one hand to my firm breast, alternating between stroking and kneading it. I took that nipple, hard as a jellybean now, and rubbed it between my fingers, pinching it and playing with it. I drifted that hand across to my other breast, feeling how rough and crinkled my areolae had become, pinching, rubbing, kneading them; feeling my flesh move and wishing it was my brother's hand doing it.

I took my fingers from my clit and licked them, tasting my own juices. I made sure I had plenty of spit on them and poised them back at my bud. I put the two fingers of my other hand down to my pussy and placed them between my labia. My eyes were shut and I could see him in my mind's eye, my big brother's face above me, his huge prick ready to plunge into my expectant pussy.

"Oh yes Jack," I breathed."Stick that dick in me, brother. Fuck me with your big, hard cock."

I gasped as I slid two fingers inside myself, imagining it was his prick, my other fingers rubbing my clit as I did so. My motions got faster and faster, picturing his length plunging into me, the fingers frigging my clit a blur. I could feel the tension in my body, the heat building up inside me. I was so close.

"Yes Jack, do it baby" I moaned. I was nearly there... so close... my fingers moving so fast, my breathing coming in gasps. Nearly... there...

Bang!

I heard the noise, but was so lost in what I was doing I couldn't recognise it for a moment.

I heard footsteps downstairs, realised that it must have been the back door slamming.

Fuck! Fuck fuck fuck! I was so fucking close.

It sounded like Jack, and could I hear the footsteps as he came through the kitchen into the hall. It was definitely Jack: the footsteps were male, and the tread wasn't as heavy as Dad's.

Could he have heard me moaning his name? No, surely not. The kitchen was too far away. And I'd been relatively quiet. At least I hoped I had..

What if he wanted to talk to me about something? About this morning? Or about his birthday?

Feeling panicky, I slipped out of bed and scrabbled around for my clothes. No time to get anything out of the wardrobe. I just grabbed for the school uniform I had thrown off so gleefully earlier and started pulling it on as quickly as possible. I had my skirt on and the blouse on - but unbuttoned - by the time I heard his footsteps head into his bedroom, across the hall from mine. I let out a sigh of relief.

I sat down on my bed, trying to calm down my breathing and waiting for the flush to leave my face,

It was then, as I sat there waiting for my breath to return to normal, that I had an idea.

Perhaps at any other time I wouldn't have gone through with it. But today, this strange combination of factors meant that I would. Maybe if he hadn't joked about that blowjob this morning, or if he had come home just five minutes later and I had actually had the massive orgasm I was heading for....well, perhaps then I wouldn't have done what I was going to do.

I agonised over what to wear. Should I dig out an extra-tight T-shirt and tiny little denim mini-skirt from the cupboard? No time, no time! I had to be in Jack's room right now. Anyway, if Jack was going to go for this, it would be because he wanted to do it with me, his kid sister, not some imaginary slut.

I wriggled back into my white cotton underwear. No bra, I decided. I did up my school blouse, leaving an extra couple of buttons undone.

Makeup? I glanced at my dressing table. Lipstick, foundation, blusher. Lipgloss, mascara, concealer. There was nothing I wanted to conceal. But what did I want to emphasise? Should I make myself up to look extra tarty? Bright, scarlet, cock-sucking lips? No time. I had to do this before my nerve broke.

A quick spritz of perfume to hide any smell of sex? Done.

* * *

I walked those few steps across the hall to Jack's room, my bare feet silent on the carpet.

I raised my hand to knock at his door, hesitated. Could I go through with this? I completed the action, knocking on the wood before I could let my doubts overcome me.

"Come in, sis."

How did he...? Of course, he'd seen my rucksack downstairs.

I stepped into his room. Closed the door behind me with a soft click. Stood with my back against it.

I looked at my brother. He was tall - taller than me. I'm about 5'7" and he must have been nearly six feet tall. 5'10 or 5'11". His hair was dark, but lighter than mine, dark brown rather than my raven black, and he kept it short. It looked a bit damp, as if he had had a shower recently. The late afternoon sunlight lit the skin on one side of his face making it almost glow, casting the other side into deep shadow. It highlighted the muscles on his body, their contours visible through his T-shirt. They weren't bulky like a weightlifter, but smooth and taut like somebody who kept themselves fit and played a lot of football, which is what my brother was. Right now, he looked incredibly handsome. Impossibly desirable.

His hair was nowhere near as damp as I was, and no shadows could be as dark as my plans at this moment.

He raised a single eyebrow, quizzically, asking a silent question.

"Um... Jack?"

"Yeah, Angie?"

"Ah... can we talk?"

"Sure. Take a seat." He indicated the swivel chair by his computer desk. I dumped what was on it into the floor and sat down, while he perched on the edge of his bed.

"What is it? Trouble at school? Need some advice?"

"No. It's nothing like that." My heart was beating rapidly in my chest, and my face felt flushed again. I took a deep breath. Another. I felt like I was going to pass out.

"Are you OK?" he asked, his voice full of concern.

"I'm fine."

I hesitated, my heart still racing. Was I really going to ask him? I could still chicken out. It wasn't too late. He couldn't reject me if I said something else, anything else. If I asked him if I could come and watch him play football or something. But, no. That wasn't what I was here for. I screwed up my courage and carried on.