All characters in this story are over 18 years of age.
Part 2 explored some peeing games and light spanking. In this part Sam and Rosie continue on that theme and add some teasing and desperate sex.
*
Real life got in the way for a while. Sunday passed, Rosie had to go home, we started the work week. Every now and again, we'd tease each other by 'phone. It got so I'd get horny just seeing her number on the screen. The first time she just said: "My cunt wants your cock." And hung up.
I called her five minutes later. She giggled when she answered, and I said "Not interested. Talk to you later." I heard her laugh aloud as I hung up. She sent me a text: "Bullshit! You're such a dick, Sam."
This kind of thing went on through a slow Monday. Later in the day, she called me again. She said: "I'm in private, are you?" I was. "Good. Picture this. I'm wearing pale blue panties, that is I'm almost wearing them because they're in the way of my hand which is touching my pussy."
"Horny."
"Mmm, Yes." Her voice was breathy. "My nipples are aching, pressing against my blouse. I'm wide open down there. Tell me what you'll do to me next time."
"Easy. I'm gonna put my cock up your bum."
"And?"
I hadn't thought this through so I made it up as I went along. "And push. Until my pubes tickle your asshole."
"Mmmm."
"I'm not gonna cum in there though. I'm gonna fuck your ass until you're sore, but I'm gonna pull out and piss on your tits."
"Oooh. What will I be wearing?"
"A business skirt and blouse." I'd guessed that's what she'd be wearing now.
"Mmm... Tonight?"
"Maybe. Unless there's something on TV."
"Bastard! Oh ff-ffuck... Sammie, I can see it all. Oh mate, I'm... Nnnghh."
I listened at the little squeaks and moans, then she said: "Oh shit! I just came! Hahaha. Whew! That was hot! Hey bro, how's your cock?"
"Aching."
"Don't you dare jack off! Bring it to my place tonight. OK?"
"Yes, ma'am."
We didn't even change out of our work clothes. As soon as her front door closed, Rosie wriggled her tight skirt up onto her hips.
"Ooh, those for me?" I nodded towards the stockings and belt she wore. They were sheer black, contrasted against her white silk panties.
"No, they're for the bloke next door. Wouldn't waste my time with you... Nghhh!"
While she was teasing me, I spun her around and up against the wall. I was no more than an arm's length from the door, but I'd been nursing an aching hardon for hours and needed release.
I dropped my pants and boxers to my ankles and pulled Rosie's panties to her thighs. She giggled as she bent to offer me her pussy, and in one thrust I was deep inside her.
She moaned, I grunted, and we began to fuck slowly.
I reached under her white blouse and roughly pushed her thin bra up so I could cup her tits. Her hips pushed at me, matching my thrusts. I'd told her earlier that I was going to do her ass, but my urgency and the sheer incredible heights her pussy took me to changed my mind. As I drove my cock into her, my thighs began slapping her butt and making little shock waves. Still I resisted the temptation to let loose, an effort that itself made my cock burn all the more.
I didn't know anything except that my cock was invading my sister's pussy, I was pawing her tits, and my balls hurt with the need to lose their load inside her. Incest. There, my mind said it. It's incest, me fucking my sister, she fucking me, and now... Boiling incest jizz raced along my shaft and erupted in my sister's womb like a wave of carnal desire. My pubic bone was hard against her ass, all my cock was engulfed, and the burning ejaculation made my thighs tremble as it pulsed.
Even when my balls were rid of their burden, I stayed up inside her. I've never experienced a double but that day, and often with her since, I've felt like the orgasm had a very long tail even before the afterglow set in.
My heart thumped, I panted for breath, and my dear Rosie just gently ground back at me while my senses broke through the orgasmic fog they'd retreated into. I realised we hadn't even got our shoes off yet, and my mind flashed back to the sound of them scraping the polished wood floor in our mad fuck-frenzy.
We'd ended up with Rosie pinned against the wall, her head protected from bumps by her arms. Now she reached behind her neck for my head, and whispered: "Stay there. I've got a surprise."
Three seconds later a hiss announced what it was. Rosie emptied her bladder with me still part-hard in her cunt. I didn't care that her pee ran in streams down my thighs and over my pants and shoes. This was Rosie's piss, my sister's piss, and that made it all right.
She moaned in relief, it lasted maybe seven or eight seconds then stopped.
"You dirty little bitch!"
"Tell me you hated it."
I answered by pressing my half-hard cock inside her some more. It was squishy wet in there, and again I realised the liquids running between us were my cum, her pussy juice, and her pee. I didn't warn her, and added a fourth. While still inside her, I spurted piss once, twice, then a short stream which cascaded out of her and joined hers along my thighs.
"Ahh! What a bastard you are!"
"Tell me you hated it."