When I worked at a comic shop, I dressed up as Black Canary one Halloween. She wears a leotard and fishnets. One of the regulars "dropped" his keys and went, "Hey, Gayle, could you bend over and pick those up for me?"
I kicked them behind the counter. His face as he realized no, he would not be getting them back until I wanted to was fantastic.
Same shop, different day, a dude comes in who won't even talk to me if the male comic guy is working comes in with his girlfriend. She is asking "Hey, we're going to dinner, right?" and he's going, "Yeah, yeah, just let me look around."
He gets a STACK of trades. A couple hundred dollars of books. As I'm ringing him up, he turns to her and goes, "Okay, we're not going to dinner because I want these instead."
She gets mad, obviously, and he tries to play down his dick move. I finished ringing him up, bagged his books, turned to her, and said, "You should dump him."
The girlfriend gives a little, awkward laugh and goes, "Oh, haha, yeah."
"No, I'm serious. This is an asshole move. You should dump him. You can do better than a guy who does this to you."
He called the shop the next day, apparently, and yelled that I'd caused his break up. The owner asked what happened, then said, "Yeah, I'd have told her to break up with you, too," then hung up the phone.