Leighton Meester hung out at Santa Monica this weekend, and thankfully, the weather was warm…which means…she was rockin’ a bikini. She looks really hot. Firm. Yum. Sorry, got a litle caught up there. This girl has a great butt, you could bounce a quarter off it. Go check out more bikini pictures of Leighton Meester’s butt, there are some nice closeups.