Heidi's Got the Hills to Pay the Bills

3/8/2008 1:30 PM PST
Although Heidi Montag just graced the cover of a major magazine to say she was "betrayed" by Spencer -- Montag and Mayor McCheese were together at LAX Nightclub in Las Vegas last night stinking up the dance floor.

Heidi once again wooed Spence by lip-syncing a song for him -- but this time, it wasn't her horrendous single. It was "Baby Got Back."