TMZ caught L.C.'s hanger-on, Audrina Patridge, alone on Valentine's Eve in Hollywood -- offering "no comment" about her press-possessed co-stars, Heidi and Spencer. John Mayer flies into Katsuya, where he let loose with some TMZers.
In NYC: Mariah Carey walks the streets ... and she's calling us "slicksters."
In Las Vegas: Brody Jenner passing vodka, and across town, one of his many exes, L.C., is attempting to get the party started.
TMZ's perky checkerboard-heeled Andrea, caught leaving Katsuya (where she was hangin' with the Mayer) -- where she told our cameras she believes Brit "just needs a little extra attention." Just like Andrea ... which is why she's in Star Catcher.