Tonight at work Byron came up to me and told me a story.

Byron: Okay, so a few weeks ago this guy came in on a half price night and rang up like, an $80 tab. So then we he leaves he writes his number on the back of the check and then tips me like, $4.
Me: Get out!
Byron: So now he's sitting out there again with a friend, and he refuses to look at me.
Me: He won't look at you?
Byron: No! When I asked what they wanted to drink he asked his friend, "What do we want?" and looked away from me.
Me: How rude. Do you want me to spit in their drinks?
Byron: I just don't understand why he would tip less than 10% and leave his number.
Me: Um...maybe he wanted you to call him and then he'd give you the rest of the tip?

The guy eventually ended up leaving before his friend and she tipped very nicely. But if you've ever had the thought, "Hmm, maybe if I tip horribly that cute server will totally call me and go out with me," don't act on it.