Museum galas tend to be stiff, dignified affairs where not much happens except very serious people pontificate about the importance of art in these turbulent political times, tuxedoed patrons pay tribute to tuxedoed board members, and a few fabulous young people, usually colorfully dressed artists, are thrown into the mix to liven things up. Well, the Whitney Museum of American Art took things up a notch on Tuesday night, perhaps the end of its Biennial next month. In between the artists (Jeff Koons, Larry Bell, Raúl de Nieves), the philanthropists (Laurie Tisch, Brooke Garber Neidich, and Neil Bluhm, who was being honored), there was a sizzling cohort that wouldn’t have felt out of place at a fashion party, surely thanks to the fact that Michael Kors and Audi were among the evening’s sponsors. Besides Alek Wek, spectacular in a white Kors suit, there was also Hilary Rhoda, Katie Holmes, Cleo Wade, Gabriel-Kane Day-Lewis, and Paul Sevigny, who seemed to be having a ball with another figure from the early Aughts, Cory Kennedy. In the end, the museum raised $5.1 million, though no word yet on how much Kennedy pitched in.