Author's note: The following story is mostly true. It happened nearly ten years ago, so I'm a little fuzzy on some of the details (Thus the 'mostly' connotation). All participants are over the age of 18. Some names have been changed to protect the guilty.
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"I need a shower. Wanna join me?"
My girlfriend of two years, Krista, grinned goofily while asking this. We were over at her parent's place keeping an eye on her three younger sisters.
"As much as I'd like to, hon," I said, kissing her lightly, "I don't have any clean clothes to change into afterwards. I'd rather not have to get back into these dirty ones."
"Suit yourself." She walked away but turned as she got to the door to the bathroom. She smacked her ass, knowing I was watching. I really liked her ass and told her so frequently.
Krista was the oldest of four girls. She was a half inch taller than me with shoulder length brown hair and brown eyes. I'd recently convinced her to dye her hair red, which looked fantastic on her. She thought she was fat, but at a hair over 120, I thought she was perfect.
Eight years beneath her and the youngest, Sienna, was the penultimate tomboy. She was into more sports than the rest of her sisters combined. Unsurprisingly, it would turn out later that she was gay. No stereotype there.
Alice, a year older than Sienna, became the troubled middle child. Diagnosed with multiple mental problems from a young age, she was still fun to be around. She was the gothic/rocker chic, with dyed black hair. She also liked to wear spiked black leather bracelets and chokers. As much as that turned me on though, it was Kayla that got me the most.
Kayla stood about 5'6" tall and weighed near 110 lbs. Blessed with an awesome metabolism, all of the girls were thin but it was Kayla that looked the best. She was always hiding her wonderful 36C breasts under tight shirts and sweaters. Her ass though, the object of my unhealthy obsession, was a vision of beauty. She never really exercised, that I knew of, but her butt was small and tight, no extra jiggle that I could see. Trust me, I watched it a lot. I still do.
My relationship with Kayla was a little weird. She was playful and flirtatious while I was a lot more reserved. She was always doing things just to get a rise out of me. Yes, the innuendo is intentional. Far too many times, I'd seen her walking around in just her panties and a t-shirt. At first, she said she hadn't known I was over. After a while, she stopped making excuses all together.
She never openly expressed any interest in me. I was her sister's boyfriend after all. But I constantly got hints that she would not be opposed to a more physical relationship.
So there I was, sitting on the couch in the living room, watching TV, when my infatuation planted herself right on my lap. She was wearing a loose fitting flannel shirt, buttoned up all the way, and a pair of tight denim jeans. I was surprised, though not completely upset by her presence.
"Hey there," she said, "what ya doin'?"
"Well obviously, I was watching TV." I rolled my eyes. "But now there's a royal pain in the ass on my lap, blocking my view. What about you?"
"Well by the look on your face, I'd say I was bugging you, but that can't be true because ya like me so much." She giggled. My heart fluttered. I soooo loved her giggles.
"My liking or disliking of you has no bearing on the current situation. Get off of me." My hands were on her hips, simultaneously holding her close and getting ready to push her off.
"What if I don't want to move?" She wiggled her ass, digging it into my crotch. "What ya gonna do then, huh?" She turned, sitting side-saddle on my lap now and placing one arm around my shoulders.
"I could just dump you onto the floor." I thrust my hips upwards, moving as if to do just that. She squealed and brought her other arm around me to hold on, crushing herself to my chest. I sat back down, her ass still firmly planted over my rapidly hardening cock.
"See," she said after calming down, "I knew you wouldn't do it." I did notice a sparkle of mirth in her eyes as she said this. For half a second, I thought I saw something more but dismissed it.
"Still, I think you should get off of me." I knew if she didn't feel me, she would soon.
"But I'm comfortable," she pouted. "Besides, I'm not moving. So there." She stuck out her tongue at me.
"Then you leave me no choice." She shrieked as I began tickling her. She wiggled and laughed, trying to get me to stop. I straightened my legs out and angled my hips up. She slid to the floor at my feet.
Caught up in the fun, I sat on top of her. I tickled her all over: her sides, her stomach, even the back of her knees. But she struggled even more when I moved my hands to her inner thighs. To stop me, she trapped my hand between her legs, extremely close to her crotch. A slight movement of my finger and I could feel the seam of her jeans where they met at the middle.
We stopped, staring at each other. Both of us were breathing hard, but it seemed to be something more for Kayla. Her neck and face were flushed. Her hands, which were trapped at her sides under my legs, had grabbed my ankles. It was almost as if she didn't want me to move.
She calmed down and released my hand. I was, maybe, a little slow pulling it out. I sat there on top of her for a minute. Then a very bad thought popped into my head. Well, bad for someone who is dating this girl's sister. A wicked grin plastered itself on my face.
"You know what I hate?" I said.
"What?" Kayla panted. I noticed her thumbs rubbing small circles on my ankles, near my Achilles tendon.
