Mary-Kate Olsen was on Letterman last night, to promote The Wackness — the movie in which she makes out with Ben Kingsley — and she was kind of awesome. She talked about how she went to high school with Spencer Pratt and it was clear that she never really liked him. She was ready to really dish with Dave about it. (She mentioned that he had a "really bad temper" and would leave soccer games in the middle of them.) Also, she was looking super healthy, and not scary skinny. Mary-Kate FTW!