Rachel Gets DPed

"... double stuff this little minx. You wanted her ass, right? I'll take her pussy. Let's see how she handles the double stuff."
Tommy grins stupidly and high fives you.
"Sounds like a good plan, man."
Rachel is in a complete daze and apparently hasn't heard your plans. She lays on the bed, gasping in deep breaths. You lay down in the middle of her bed and pull her limp body on top of you.
"Come on, babe, ride my cock."

Still dazed and confused, Rachel weakly climbs onto your stomach. You grab her hips and lower her pussy down on your hard cock. She whimpers as you penetrate her. She slides down your cock and soon you are buried to the hilt. You move your hands to her ass cheeks. You thrust up, raising her waist off the bed and use your hands to spread her cheeks apart.
"Let's do this, bro."
Tommy climbs onto the bed behind Rachel and lines his spit-covered cock up with her tight asshole. He grabs her shoulders to steady himself and stabs his cock forward. Rachel screams and Tommy's cock pops into her bowels with yours still lodged in her pussy.
"Aw, fuck man, this is incredible."
Tommy pushes forward and his cock slowly disappears into Rachel's ass. Once you are both buried to the hilt, Rachel collapses on your chest, panting and crying. Tommy begins slowly but forcefully fucking her ass. Each time he pulls out, Rachel's ass grips him so tightly she is lifted up your cock. Each time he slams down, Rachel's pussy is pushed back down your cock. You can feel each time he thrusts into her. You begin grinding your pelvis upwards, fucking your sister.

"Her ass is so tight, man!"
Tommy reaches up from Rachel's shoulders and grabs her hair. He pulls until her head arches back and he can see her face. Her eyes are closed and her mouth hangs open. Her expression is a mixture of absolute bliss and obvious discomfort. As Tommy lifts her up by her hair, her breasts end up in your face. You suck one of her nipples into your mouth and lick and bite it.

You continue fucking Rachel like this for several minutes. Tommy is now really slamming into her ass while you grind your 10 inch cock into her ravaged pussy. Eventually though, you've both had enough and can feel your orgasm rising.
"Shit dude, so good, I'm gonna cum man."
Tommy begins hammering away faster into Rachel's ass.
"Me too, dude. Where should we blast her?"