Don't skip pickup on a bad date. If your date says "I'm going to the bathroom, can you get the bill?" that likely means they are about to skip and you will be left with the bill.

For a bit more context, I recently had a normal and pleasant looking woman do this to me. As soon as the bill came she said "excuse me, I'll be right back!" And then she didn't return. I showed her text messages to the server but he was sympathetic but unwilling to do anything. I was fuming.