Feb. 11, 2007 | 01:00 AM EST

Justin & K-Fed's Red-Carpet Run-In

Photo by: Kevin Mazur / WireImage
Justin & K-Fed's Red-Carpet Run-In | Justin Timberlake
Awkward much? As Justin Timberlake made his way down the carpet into a special Friday night performance at Hollywood's Avalon, he came face to face with his ex's ex: Kevin Federline. The two – who've recently made a habit of crossing paths – exchanged a brief hug, then K-Fed motioned to the press to keep it quiet, signaling "Shhh" with his finger. Timberlake, on the other hand, was just getting the noise started at a party that was so packed not even Jude Law could get in.

After the Black Eyed Peas played, he joined Nelly Furtado and Timbaland onstage for "Promiscuous," beat-boxing into his mic. As Furtado slipped backstage he and Timbaland went right into "Sexyback," getting a nod of approval from a shades-wearing Diddy and had Scarlett Johansson, clad in a flowy black top and with cocktails flowing, on her feet throughout his entire performance. Also there: Grey's Anatomy costars T.R. Knight, Kate Walsh and Sara Ramirez, who was grooving solo against the guard rail; Nick Lachey and Vanessa Minnillo, navigating the VIP balcony with a few bodyguards; Kid Rock, smoking a stogie and getting a little cozy with a brunette; a Mischa-less Cisco Adler, standing in the aisle and jamming to every song; and Paris Hilton, deftly making the social rounds. And where did K-Fed end up? Standing against a wall outside the VIP area – gamely chatting up a brunette.