Photos and Video of Mary-Kate Olsen on The Late Show With David Letterman

Mary-Kate Olsen kept up with her new strategy — all smiles all the time! — on her way into The Late Show yesterday. She looks gorgeous showing off the grin alongside those stems. Olsen teeth used to be a holiday, but now it's standard fare, and that cheery attitude carried right on into the studio to chat with Dave promoting The Wackness. MK was admittedly a bit jet-lagged flying straight from the Samantha Who? set but still managed to be charming and funny talking about making out with Gandhi. Plus, she admitted that she went to high school with Spencer Pratt but didn't have much positive to say about that — check out the video below. Love her.