rough scissoring

"...scissoring, and they were screaming as loud as possible. And each one had a handful of the other's hair and they were just yanking each other toward themselves." She shrugs, "I just wanted to let you know that that turned me on." And then her tongue slicks over the tip of your cock again. She goes back to work.

You should let her work. But you can't help yourself. You have to know more. "Have you ever done anything like that?" You ask. Your cock is throbbing.

"I wish" she says, her mouth half-filled with your dick.

Your mind races. You could suggest... could you? Should you really suggest that? And maybe it's because your girlfriend's sister is currently worshipping your cock, but you feel a bit invincible, like you could say or do anything.

So you say it. "You should do it."

Tess slips her lips off of you again. "Yeah... maybe one day. I'll let you know if I do it."

"No." You clearly didn't get your point across. "You should do it right now."

"Ha!" Tess feigns a laugh. "With who? Katie?" She's not serious. But you are. You don't respond. You let the silence answer your question. "You mean it, don't you?" She says, and you sense you're starting to lose her, just as you thought you had an opening to get control of the situation. "You think I should have sex with my sister?"

But there's something to be said about the fact that she's not screaming 'No! No! Never!' She doesn't seem incensed or appalled at the suggestion, just a little surprised. She's just asking you to calmly confirm your request.

You look over at Katie. She's still sitting in her chair, leaning in toward both of you. She's paying very close attention. What, you wonder, has been going through her head this whole time?

"I don't know if I can have sex with my sister." Tess bites her spit-covered lip. She seems turned on right now, but she's hesitating, as any reasonable person would. Wouldn't you?

"Well... I have an idea that might make it seem a little less naughty." You say.

"Don't get me wrong." Greenie interrupts. "I like naughty. But my sister... I just never... what's your idea?"