Amy interrupts

Amy pushes you back away from Ellen. "Sorry Scott, it's a free for all now and I want a turn with Ellen next."

"Be my guest," you say, not about to stop the two girls from fucking each other right in front of you.

Amy descends upon Ellen, kissing her and then licking your cum off of her cheek. Ellen moans under Amy's attention as the redhead nuzzles her neck and rubs her breasts. Amy presses her pussy up against Ellen's and the two roommates begin to writhe together, rubbing their vaginas together in an erotic dance.

You kneel behind Amy and rub her undulating ass, then slip two fingers into her pussy as she fucks Ellen.

"Fuck yeah, Scott," Amy gasps, pleasantly surprised by your addition to the equation.

"Oh, Ames, oh fuck you're so good," Ellen moans.

"Fuck Ell, your body is so hot," Amy murmurs into Ellen's neck. "I want you to cum. I want to make you cum."

"I'm cumming..." Ellen gasps. "I'm cumming Amy, I'm cumming for you!" Ellen's hips buck against Amy as the blond girl shudders with a massive orgasm. Amy is close behind, cumming a moment later as you continue to finger her rapidly.

Ellen collapses beneath Amy, leaving Amy's upraised ass exposed before you. You could fuck her from behind, or you could push her aside and fuck Ellen instead...