sunglasses Kristin Cavallari brentwood jacket gy the hills

THIS is how great she looks after sweating her ass off at a spinning class!

We snapped the Hills starlet leaving the gym with some gal pals, and while most celebs would be furious at photogs for catching them in this uh, ripe and juicy state, Kristin didn't seem to mind at all! I guess when you look this good minus the makeup, you don't have much to worry about!