[Miscguy]

I would have said pretty much the same things. Perhaps just differantly. In the first situation you could have put it a bit differantly, something along the lines of...

"You do realize that he doesnt want to go to the dance with (chick) because hes gay, right?"

BAM problem solved, now the girls will love him because hes "not threatening", and hes off the hook with the nasty chick.

Situation two requires a bit more grace and civility.

Dumb bitch: "if you can't find anybody else I will go to prom with you".
You: "Oh fuck that, all you did last time was try to fuck other guys all night."

Again problems solved, now she hates you and you never have to put up with her shit again. Fuck that bitch and her "busy" schedule.