Jennifer Aniston started 2009 in Los Cabos, Mexico, surrounded by her closest girlfriends — and boyfriend John Mayer.
The Marley & Me star, 39, shared a villa at the El Dorado Golf and Beach Club with Courteney Cox, 44, Laura Dern, 41, and Sheryl Crow, 46. Courteney and Laura's hubbies, David Arquette, 38, and Ben Harper, 39, were also on the trip.
After lounging poolside Dec. 29, Jen took John, 31, who was staying in a nearby villa with his two brothers, to a birthday party on Dec. 30.
Jennifer has told her pals to embrace her relationship with John — or else, an insider tells OK!.
"With the way Mayer behaved after he and Jen split last August, some of her friends were horrified when they got back together in October," says the insider.