How about this one?

[justathought555]

A man and a woman (close friends, but only friends) are sitting in a restaurant/club/bar, and the woman is trying to cheer up her friend. He is depressed over the breakup with his most recent girlfriend. She trying to encourage him, i.e. - "She's hot...ask her to dance" or "Over there - She's checking you out", but he is still wallowing in his misery.

He finally gets fed up with this, and says "If you think she is so hot, why don't you ask her out."

She finally gets up to see if she can break the ice for him....

Some of the possible variations from here:

The ice is broken, but between the heretofore straight female half of the twosome and the woman 'over there'; or

The other woman thinks that she is being propositioned by a couple, and nibbles on the bait, but is only interested in hooking up with a couple. An additional twist here would be that the female half of the twosome is openly lesbian, but is so enamored with the new woman that she considers convincing her male friend to go along for a one-night adventure for them both;

For fans of incest stories. the twosome could be brother/sister or cousins;

and so on.

Whaddya think?

 

[sirhugs]

promising, though I prefer the version where the gal doing the picking up is straight, not even bicurious, and her appeoach is intended just to accept the dare, not intending to go through with sex, but the situation gets out of control.