10/25/2010 at 04:00 PM EDT
After performing at Justin Timberlake
's charity concert in Las Vegas, newly single Christina Aguilera
was still in the mood to party. The singer took her crew of dancers and close friends to Tao to blow off some steam. Aguilera sported a skintight dress and waved to the crowd from her skybox as the deejay gave her a shout-out, announcing that the "sexiest lady in the world is in the house." The crowd also snapped pictures of Aguilera, who stayed out until almost 3 a.m.
was enjoying a night out too – at the Mondrian Hotel in L.A. The singer stopped by SkyBar with a younger guy but sans entourage or security. Spears, who sported a green turtleneck, stuck to juice and hung out poolside, occasionally approaching the deejay booth to check out the action as DJ Lindsay Luv spun.
went out with his guy friends, hanging out at the Saturday Night Live
afterparty at Matsuri inside New York's Maritime Hotel. The singer and his buddy snacked on a huge platter of sushi and mostly kept to himself, ignoring other revelers like host Emma Stone
and Blake Lively
. Mayer later whipped out his American Express Black Card and split the bill with his friend.
Lively, meanwhile, was doing some candle shopping with her Gossip Girl
costar and real-life boyfriend Penn Badgley
in N.Y. The couple stopped into Henry Bendel's where they loaded up on the store's signature holiday candles and also New York City Trash, a white chocolate-covered snack mix.
It was a Real Housewives
bonding session at Red O in L.A. where New York City
star Bethenny Frankel
was dining with Beverly Hills
's Kyle Richards.
The ladies, who have been friends for years, were seated with a handful of guys, but talked amongst themselves and also laughed and happily chatted up fans who approached.
By JENNIFER GARCIA, MARK GRAY, CARLOS GREER, LESLEY MESSER and DAHVI SHIRA