My workouts became more intense each day as the big night approached. I am not talking about the big night, which most high school seniors look forward to, High School Prom, but my first defense of my amateur division championship in Thai kickboxing. After winning the championship, I had taken a little time off and began training casually but in three weeks, three days after Prom, I would fight again and I needed to be in peak physical shape.

Sweat drips from my chin as I kick harder and harder at the heavy punching bag that hangs from my garage ceiling. I had lost ten pounds in the last couple of weeks as I dropped down to nearly zero fat on my body. Sandy, my new girlfriend, does not like me training so hard. She says my cheeks become shallow, my veins show up more, and my eyes seem not to focus on her. Sandy and I have been dating for less than a month now. Not long enough for anything to happen since I have been so busy with school, preparing for college, and training. Ever since my championship and my winning streak were first reported in the LA times, Sandy had begun to notice me. Generally quiet and introverted, I usually avoided girls like Sandy but she is the captain of the cheerleading team and like most guys my age my hormones speak louder than my head (or at least the head on my shoulders). Every guy at school is jealous of me for the first time in my life. It feels good.

"Hey Tiger. Kill it yet." My sister asks as she walks into the garage, seeing me kick the hell out of the punching bag. "Ready for a break?" My sister and I are the same age. My father was a marine and left my mother to go on assignment in Thailand. They were not married and her parents had always objected to her dating a marine. Since he would be gone at least a year, my father figured a break up would be the easiest way. He thought it was over between him and my mother and quickly began a second relationship with a beautiful teacher in the Thai province known as Korat. When he returned a year later, he discovered I had been born and quickly married my mother. Fortunately, despite the rushed wedding they have been relatively happy ever since. Eight months after returning to Los Angeles, he received a letter from Thailand, which sadly read that the teacher had died giving birth to his daughter, my sister. Her grandparents brought her over and moved in with us. Her grandfather, luckily, is a world-renowned coach in kickboxing.

My sister, Cat, got her slender build and beauty from her mother but she is nearly my height and her breasts are definitely more American than Asian, a gift from my father's side. "Ready for tennis?" she laughs, lifting her tennis racket with a smile. It was customary for me to warm down by going out to the tennis courts with my sister. We had grown close from the many hours together and felt like we could chat about anything.

"Yeah, sure, sis." I pull off my gloves and ran inside to change into tennis shoes and clothes. The thought of my sister in her tennis outfit sticks with me each time she shows up in the garage. She sure is beautiful. Her long silky jet-black hair and healthy tanned skin give her that wildly exotic look which guys find alluring. She is on the cheerleading squad with Sandy, although Sandy is probably four or five inches shorter and heavier especially in the breasts. Cat's tall slender tightly curved body probably gets as many stares as Sandy's voluptuous breasts. Sandy has light brown hair and amazing breasts, normally I might say they are too big since they definitely have a mind of their own when she is out on the field cheering the team, but since she is almost my girlfriend, I couldn't imagine them being too large.

As we start volleying back and forth across the net, alone on the court for the first time in weeks, my sister says something, which surprises me and makes me hit the ball wide. "I have decided to have sex with Derek on prom night." My sister and I have always talked openly about sex and had decided a long time ago to tell each other when we were going to have our first time. Derek was the quarterback of our very successful football team and had received scholarships to Nebraska, UCLA, and Washington. He and my sister had never really dated but he asked her to prom last week and she accepted.

"You don't even know him really," I blurted out rather awkwardly, strangely I suddenly feel jealous of Derek. "Why would you want your first time to be with him?"

My sister hits another ball across the net, her graceful swing catching my undivided attention as her long smooth legs move to keep her in front of my return volley. "I figure since you are planning to sleep with Sandy, I could lose my virginity that same night so we both have something we could chat about the next day. Otherwise, you probably won't tell me the details about it and I definitely want to know." Her logic seemed strange to me but I listened. "Besides, I've had a crush on Derek for four years now and we have been friends for longer than that. Just because we haven't dated won't make it less special. I've always wanted to lose my virginity at the Senior Prom. You know that. Can you think of someone better than Derek for me."

The answer in my head causes me to lose focus. I want to say I would be a better choice than Derek but even thinking that nearly causes me to blush. We hit back and forth silently for several more minutes before sitting down on the bench. A drop of sweat ran from my sister's neck to the valley between her breasts and luckily I look away before she notices me staring. "Do you think I should wait?" she asks.

I shrug my shoulders. "You know Derek creeps me out. Too many girls like him and he flirts with all of them. He would never be faithful to anyone."

My sister laughs and gives me a playful shove. "You know I don't like Sandy. Her boobs are huge and all the boys stare at them." I smile. "She makes mine look small out there when we are cheering." She gestured to her own beautiful breasts.

Suddenly, I felt I had permission to look, so I do. "Yours are even better than Sandy's. They are bigger than most girls and perfectly shaped." Although I feel like I am on strange ground I continue. "Her boobs flop too much when she jumps. I'm always afraid she is going to hit herself in the eye with those things. Besides, they have to be fake right."

"No, they are real big brother. I promise you that. You'll be lucky enough to find that out soon."

I blush and look away. "I honestly like your boobs more than hers."

It is her turn to look away and blush. "What a nice brother you are." She turns back and gives me a big hug. I am acutely aware of her firm breasts pushing against my chest. Although we are both hot and sweaty, the smell of her hair as I lean across her shoulder makes me suddenly dizzy and I hold the hug longer to enjoy her perfume.

"Whatever makes you happy, sis. That is what I want for you." I cringe at the thought of her with Derek but accept that she has liked him for a long time.

"Promise me," she says. "You will give me whatever makes me happy?"

Our close hug is beginning to give me an erection so I brake away and nod, smiling into her gorgeous dark brown eyes.

I think she notices my shorts but looks away. "Remember, no sex with Sandy until Prom night. I want both of us to have our first time on the same night. Agreed?"

I smile again. My sister is adorable. Her soft voice makes it impossible to disagree with her.

"Agreed."

On Saturday, the week before Prom, I pick Sandy up at her house to go see a movie. I heard that scary movies make girls horny and since I was already in that mood, I take her to a horror show. Sandy is wearing a tight T-shirt and a blue miniskirt, both of which show off her enormous curves. Only by using every ounce of willpower can I keep from staring at her breasts and ass. Although I allow for occasional glances which she obviously notices.

"How's the training going, stud?" She leans toward me and puts her head on my shoulder as we drive to the theater. Her hair smells the same as my sister's and she is wearing the same perfume as Cat. I instantly get a hard on. Must be a cheerleader thing. They must know that guys love that smell and share their secrets. Her hand settles on mine as I shift gears.

"Almost ready to fight." I answer. Her hand slowly caresses mine and then grabs the stick as well. "Sorry if we don't see each other enough. I've been really busy training."

"You have a nice stick here, champ," she smiles. I catch a faint scent of alcohol on her breath. Not so much that it is bothersome but she has obviously had something to drink before the date. Still her grabbing the stick shift and stroking it seductively made my pants bulge even more. Her breasts push against me as she slides closer. Her green eyes tell me immediately what she wants from me and suddenly I wish I had not promised my sister to wait until prom to have sex with Sandy.

The movie is OK. I place my arms around Sandy and they slip down to her chest. She doesn't object and even seems to welcome it. Casually I give her giants tits a gentle squeeze. She smiles in response. "Should we go somewhere else, more private? She asks and winks. Her hand drifts to the bulge in my pants and she gives it a little tap. "Maybe I can help out the little fighter. He definitely wants out." My mouth is suddenly dry and I take her hand as we both rush out of the theater.

"My parents aren't home. Maybe we can go there," she suggests. My mind swims as I think of the promise to my sister. I could play around little I think to myself. I didn't promise anything about that.

The tires to my car squeal as I pull out of the parking lot and rush her home. She massages my throbbing member during the entire drive to her house and we barely make it through the front door and onto the couch before our shirts come off and we are in a powerful lip lock, tongues wrapped around each other like snakes. Why did I have to wear jeans I thought to myself but Sandy's expert hands solve that problem quickly. Her silky black bra barely holds her ample breasts, which surge upward defying their confinement and seeming to oppose the law of gravity.

My hands trace the outline of her bra and reach around back, fumbling to unlatch them as I kiss her madly. I can feel their swell against my own bare chest and the passion is almost unbearable. Realizing my obvious failure, she reaches back quickly and finishes the job, shaking the bra off as it falls away. I kiss her along her neck and look down to see those amazing breasts that every guy at school wishes he could hold. "They definitely are real." I say aloud. Without hesitating I place one hand on each and feel their warmth. The large melons are too much for one hand and I lower my lips to the tip of one. I want to be gentle and loving my first time but find that my hormones drive me more than my heart and I suck savagely at one swollen nipple, biting at it as I grip the other firmly. I can feel her excitement as the nipples react to my affection.

Sandy moans in delight and grabs my swollen dick through my boxers, gripping it firmly. "The champ likes my tits I see." She whispers in my ear. "Those are as real as they get." She pushes her giant globes against my face and reaches underneath my boxers to grab my naked shaft. "Does the boxer fuck as well as he fights?" She asks in a husky voice.

My dick feels like it is going to burst it is so engorged and I push upward into her hand as I suck at the other naked tit. I am eighteen years old and I can't believe I am finally in a position to lose my virginity. Now I am with the captain of the cheerleading squad who has the most lusted after body in the whole school. Hundreds of freshmen jack off to her picture every year as the school sells its yearly calendar for a school fundraiser.

I leave her breasts briefly to kiss her mouth again and she pulls my boxers off as well as her skirt and underwear. Both completely naked in her front room, we wrestle on the couch with my swollen dick rubbing the outside of her pussy and my hands roaming all across her playboy-like physique. I end up on top feeling the full length of her body spread out beneath me. Her tight abs lead to a tuft of brown hair above her love area. I can't believe that with breasts that big she could still have a hard stomach. My hand delves into her juicy twat and I can feel the wetness cover my fingers. She pushes up against my shaft trying to force it into her hungry vagina but I reach my hand in the way and massage her clit instead of penetrating her. She grinds her hips in rhythm to my hand and I can tell she would make an expert lover. Her movements against my finger make my swollen shaft jealous of the attention. The desire to force myself into her and feel the inside of her pussy clouds my mind with excitement. "You are beautiful." I exclaim.

She smile and bites at my ear, her hand moving up and down my hardened length and reaching beneath to cup my tightened sac. "I love your big dick." My stomach dances as her finger play with my entire length. She leaves my penis alone briefly to run her nails across my stomach before holding my manhood again.

"Fuck me, champ." She growls. My head feels misty, almost like a drug high as I grab her ass and rub my dick up and down her pussy lips. Her breasts heave upwards, their weight crushing against my bare chest. Her large protruding nipples poking me with their excitement. "What are you waiting for? Fuck me now." Her voice moans as she yells out in anticipation. She holds me closer and lets her perfume fill my head with its confusing odor. She smells so much like my sister it makes me delirious. Her pussy rubs upward moving in circles along my dick as if begging it to come inside. Like an expert lapdancer, she moves her hips circularly in a rhythm, coaxing my dick even harder than before. "Your dick wants in." She moans and pushes her breasts together, emphasizing their size and weight. A drop of sweat runs down her neck as she pushes her giant breasts at me. The drop runs through the enormous valley of her tits, reminding me of the day with my sister at the tennis court and the promise I made to her. I told her I would not fuck Sandy until prom. I've always kept promises to my sister and she has always kept them with me. Sandy's burning hot pussy is so wet it covers the outside of my dick with its moisture and I still haven't been inside her.

She pushes me to the couch and quickly straddles me, trying to put my engorged member to the entrance of her waiting canal. Her sudden strength and urgency catch me by surprise and for an instant I can't decide what to do. "Let's wait until Prom night." I blurt out suddenly. The fog in my brain clears instantly and I can't believe I just said it.

She leans forward letting her breasts touch my pecs, as she whispers, "Tonight or never champ." Something in her green eyes, seems strange, as if there is something that she is not telling me. I can feel her pussy against my dick and I could push upward and know the beauty that all the other guys at school want. "My pussy is hot for you now. Prom is too late." There is something Sandy is not telling me I think. I can feel it in what she is saying. In my heart something is wrong with the situation. With every bit of self-control I possess, I roll her off me and begin getting dressed.

"What are you doing? You can have me now." She says as I walk out the door. I can't believe I just did this, I think to myself. "I am waiting for Prom." I call back as I shut the door.

As Prom night approaches I watch my sister prepare eagerly. We even go together to pick out her dress, a beautiful black gown which hugs every inch of Cat's gorgeous body. I realize how large her breasts really are as she models the silky material. I guess I was comparing her to Sandy's monsters and forgot how well endowed my sister truly is.

"What will Derek think?" she asks. The question rubbing against my nerves.

"He'll know he is with the best-looking girl in the whole school," I answer truthfully.

"Better than Sandy?" She smiles cleverly.

I nod quietly then answer aloud, "Definitely better than Sandy."

She gives me a hug and a kiss on the cheek. "Aren't you sweet to your sister. How was your date with Sandy last week?" She asks absently as if she seems unconcerned about the answer.

"Pretty hot sis. It was hard to wait. I can't believe I am waiting."

She laughs. "Don't worry, tiger. It will be worth it." She gives me a sly wink and goes back into the changing room. I notice the strap slip off her shoulder as she disappears from sight and I can only imagine the rest, as she would soon be completely disrobed. Prom is in a couple days and my hormones seemed out of control. I am constantly thinking of my sister, especially after my last date with Sandy.

Several more sexy outfits later and several hardons, which I barely managed to hide I find myself in Cat's room as she put away her new dress; she finally decided on the black silk one. I agreed eagerly of course, because she was a knockout in it.

My mom and dad are away at a dinner engagement with Cat's grandparents so we are home alone. After chatting for a few minutes about nothing, Cat asks, "Can you do me a favor?"

"Of course, Cat."

"I need to pick out what underwear I should wear at Prom."

"Model it for me and I'll tell you which is best," I say jokingly, with a huge grin on my face.

"Alright." She says with a smile, grabbing several pairs and disappearing into the bathroom which connects our two rooms.

My mouth drops. Was she serious? I wait silently for a couple minutes before she comes out in a long white bathrobe. The one I always see her in, which seems sexy when she wears it. She strolls to the center of her bedroom as I watch while sitting on her bed. I feel like I am in a Victoria secrets commercial as she pulls open her robe and lets it fall to the ground. Underneath she wears only a red bra and panties. Her brown skin shown off perfectly as she spins a couple times before grabbing the robe and disappearing again into the bathroom. The show was just a tease. I barely had a chance to look at her. I tried to clear my mind of visions of my sister in her underwear.

"Number two!" She calls out and again strides out in her bathrobe before removing it. This time tossing into the bathroom as well. I can see her nipples poke out of the thin lacy white bra and her white panties don't completely disguise the dark hair in her private area. Like a runway model she walk toward me turns, lifts her arms as she does a complete turn, and looks back at me. I doubt if the models in the magazines are as beautiful as my sister.

I can feel my dick fight its confines as I watch her angelic body turn in front of me. My eyes lock themselves onto her breasts, which seems to swell beautifully above the white lace and bounce gently as she bobs up and down. Then I watch her legs, which hypnotize me with their grace and form. At last she blows me a kiss as she disappears in the bathroom again.