Well a date revealed what a jerk he was one night when this happened:

Start of dinner, looking at menus:
Me: oh I might try the sundae after, that looks good.
Him: You should.

After dinner:
Him: Weren't you going to get that sundae?
Me: Nah, I'm too full.
Him: Oh come on, it's my treat.
Me: Well I guess I could try it.

Little while later after I eat about 1/3 of the sundae and stop:
Him: Aren't you going to finish that?
Me: No, sorry, I'm full.
Him [swearing, stands up in restaurant and swears at me and calls me names] I'M PAYING FOR THAT YOU THINK IT'S FUNNY TO MAKE ME PAY FOR FOOD YOU AREN'T GOING TO EAT [storms out of restaurant]
Me: o.o