The following dialogue just popped into my head:
A: Go fuck yourself.
B: Unfortunately, I'm not flexible enough.
C: I am. *at everyone's stares* Not that I'd do it, but I am
flexibile enough to.
D: C, will you have sex with me?
Now, to think of a story I could put this scene into...
If I'm asking for advice on a story idea, don't tell me it can't be done.