Caught in the Act!
05/24/2011 AT 06:00 AM EDT
Rihanna was solid gold in a sparkling dress while celebrating her female artist of the year award at a star-studded Billboard Music Awards bash at LAVO Las Vegas. Making her entrance near midnight, RiRi held court as industry pals and other winners congratulated her on the night, where she opened the show with a duet of her hit "S&M" with Britney Spears. Also at the bash: Mentor Jay-Z and Billboard Millennium Award honoree Beyoncé, Glee's Matthew Morrison, and Joe Jonas – who stopped by the DJ booth to get on the mic and say hello to the crowd.
Ryan Reynolds enjoyed a guys' night out on the patio of West Hollywood's Chateau Marmont, where he and his boys kicked back at a table with a group of attractive women. Looking casually chic in a fitted leather jacket, the Green Lantern star appeared relaxed before taking off with his pals at around midnight.
Also at the Chateau Marmont to enjoy a night with the fellas: Jeremy Renner, who hung out on the patio where he had a few drinks with a pal. Though he looked intense in his tough leather jacket, the two time Oscar-nominated actor seemed to be having a happy chat with his guy friend, with whom he shared a pot of coffee before leaving together at 11 p.m.
Rachel Bilson stopped into Atlantic Grill at New York's Lincoln Center for a business lunch to discuss her new CW show Hart of Dixie. The fashionable cutie enjoyed a chopped salad and iced tea.
By JENNIFER GARCIA, MARK GRAY, LINDA MARK and LESLEY MESSER