The Gossip Girl costars hit the Nina Ricci party following the Met's Costume Institute gala in New York. Plus: Katie Holmes, Paula Abdul, Paris & Benji and more

1 of 21

HAVING A BALL

Blake Lively and Penn Badgley (both in Ralph Lauren) stick together on-camera and off, attending the Nina Ricci afterparty following the Met's Costume Institute Gala Monday in New York. And while the Gossip Girl stars don't admit they're dating, Badgley told PEOPLE, "I think she's incredible. She's an amazing person and she's beautiful – so there's not a lot to dislike."

Obsessed with Gossip Girl? Get the latest.