Blake Lively, Armie Hammer Blake Lively, Armie Hammer

The Upper East Side is getting steamier by the week.

Gossip Girl's Serena van der Woodsen (Blake Lively) will soon be feeling the heat with a new man — once he's done dating her socialite bestie, Poppy Lifton (Tamara Feldman). Up-and-comer Armie Hammer will play the dashing Gabriel Serrano, who will stick around for three episodes toward the end of the season, has confirmed.

Hammer has previously appeared in episodes of Desperate Housewives and Veronica Mars, among others, and will next appear in two eps of Reaper as the Devil's son, Morgan.

What do you think about S.'s new suitor? Just her type or "he's no Lonely Boy"?

Additional reporting by Mickey O'Connor.