The air in New York was a soupy mess last night, so one could be forgiven for changing out of a burdensome sweat- and humidity-dampened ballgown after the Met Gala. Well, maybe except Blake Lively, who just wore a decorated blue Band-Aid. But she changed into a miniskirt, T-shirt, and Converse sneakers to party at the Boom Boom Room afterward, perhaps exposing more cleavage there than she had all night. Leighton Meester, Rachel Zoe, and most everyone else kept their ball frocks on. [Guest of a Guest]