Obviously

*Clap* *Clap* *Clap*

You lay, trying to relax into the poolside lounging chair as your sister fucked your ass.

She sat astride your legs, hands sinking into your soft perky bum as she pistoned her hips fast enough to make loud clapping noises every time her thighs and sack met with your own body.

You cringed as her huge dick bottomed out yet again and caused your spine to lift up as all of your internal organs re-arranged around the massive thing.

It perhaps was the wrong thing to say that it was “your ass”, it was on your body, between your sexy little cheeks, but in actuality the cute little hole belonged to your sister.

“U-uhm, sis?” you asked between body-shaking thrusts, a slightly pained expression on your face as she pierced you over and over again.

“Can you, well, go a little slower?” you pleaded quietly. While she could use the asshole that belonged to her, it was on your body and made it uncomfortable for you to receive her girthy schlong.

Glassy eyed, she blinked down at you, seeming startled by your words.

“Oh, huh.” she said, tilting her head to the side curiously as if surprised that you would say something like that. The residuals of her last belly filling climax stuck to her member, stringing up all over the sexy crack and the juicy cheeks she plumbed. The flap of your blue bikini skirt stuck to it as well, staining with the sticky substance.

“Yeah, I guess…” she mused, returning to a more even back and forth inside the stretched out hole.

Much better. You sighed, finally able to get a bit more relaxed under the noonday sun, listening to the subtle lap of the pool just a couple of feet away. You really needed to get a propper tan, it was far too long into the summer now to be missing out on such a fun little physical adjustment.

You opened your eyes looking back and forth to make sure no one but your twin would see you. Satisfied that no one was peeping on you two, you reached behind your back to undo the string that held your bikini top in place. Didn’t want to mess up your tan after all.

Caris continued to stick her overly large dick deep inside you, causing you to rock, almost like you were laying atop a floating device (but not quite). So relaxing.

You should probably be in pain right now, at least any normal human probably should, but for whatever reason the star between your cheeks and that belonged to your sis could accommodate, quite easily, large insertions. It was only when your sis got too excited and she started really thrusting that pain would become an issue like before. This however was mildly relaxing, like a massage performed on your insides… by a massive dick.

“Mmmm…” your sister moaned, the telltale sign that she was perhaps ready to unleash even more slimy juice inside of the receptive hole.

You grunted as well, feeling the massive thing crush the round bump of your prostate. Even more pre spurted out from your miniscule penis into the already sticky spot of the towel below you. However, even with the stimulation on the hidden bump, you didn’t see this as something sexual (at least not on your part). This was just your sister using the hole that she owned to masturbate, the fact that you were here was merely by necessity, however uncomfortable it made you feel at times.

Oddly, it reminded you of licking her small slit, the not-quite but kind of sexual atmosphere and, well, your sister needing you to be there to get off.

“Fuckfuckfuckfuckfuck! OH GOD I’M CUUU-!!!”

Warm, sticky spurts entered into your lower intestine as the hot and hard rod pulsed with the goo, causing a clingy warmth to burble inside your belly. You tensed slightly at the sudden change in your sister’s tempo, but relaxed again once she bottomed out, exploding inside of your sexy little form.

Your eyes darted open as you remembered something.

I forgot the lotion!