Jennifer Aniston's, boyfriend Justin Theroux, gave a penthouse party for the Hollywood actress' 43rd birthday, a source close to the couple told

Among the guests at Saturday's bash in a penthouse overlooking West Hollywood's Sunset Strip were Courteney Cox, Chelsea Handler, Jimmy Kimmel, Ben Stiller, Emily Blunt and Jason Bateman.

"She seemed very excited to see her friends, but she never got too far from Justin," an insider told, adding the room was decorated with white hurricane candles and jazz music played while the guests ate and drank.

"Every once in awhile, Justin would come up from behind and give her a big hug and kiss. They would embrace and whisper to each other for a minute but then go back to socializing. She seemed very relaxed."