Yes!!

"You're sure she wants me?...and that you want her?!"

"Oh, yes." She pulls herself toward you and presses her lips to yours. "And I want you, too."

Thoughts of having two girls at once race through your mind. It's something you've always dreamed about. And, when they're as hot and nubile as your sister and her friend, it's almost more than you can bear to argue against. Your cock is hard in your pants, and fighting to reach the hand that is resting against it.

"Ok, ok." You grab her hand and turn toward your sister's room. As you get to it, you find it slightly ajar, the light off. Your sister's friend is standing behind you, her breasts pressing against your back.