Why is Kristen Stewart so melancholy in pictures? She has a guaranteed hit movie coming out next week, is supposedly dating hottie Robert Pattinson and tween girls (and their moms) around the country want to be her. Because Kristen has been splashed on the cover of every major magazine in the past few months we have become nonplussed by the fact that Ms. Stewart rarely smiles. In fact, she always has quite the puss on her face.

We take a look at Kristen's sour pucker after the jump.