She wants you to masturbate for her.

"There's something that I've always always wanted to see a guy do," she says with gleeful enthusiasm. "I used to get myself so wet just thinking about it."

"Oh, and what thing is that?"

"I want to see you jack off," she tells you, grinning manically. "I want to see you stroke your hard cock and come all over yourself. That would be so fucking awesome."

"Awesome for you, maybe," you reply with some surprise and discomfort. "Of all the things we could be doing, you really want me to do that?"

"It's a forfeit, remember," she says sternly. "You lost the bet, and now you have to do what I say. I want to see those pants down and your hand on your prick!"

She's very adamant about it, no doubt bolstered by her current drunken state. Without dwelling on the specifics of your own solitary habits, it's safe to say that you've never performed such a thing in front of another person before.

"Really?"

"Really," she says, crossing her arms.

Well, there's really one of two things you can do in this situation.