Jennifer Aniston and Justin Theroux have been partying in Mexico with George Clooney.

The couple were among a string of famous faces, including Jimmy Kimmel, Howard Stern, Michael Phelps, Cindy Crawford and her husband Rande Gerber, who attended an annual brunch at the El Dorado Beach Club in Los Cabos for the 'Up in the Air' actor's alcohol brand Casamigos Tequila on Sunday (05.01.13), where they got to enjoy a special tasting of the drink.

A source said: ''It was for members of the club and special guests. They had a tequila tasting.''

The group had been in Mexico for over a week and also enjoyed an ''intimate dinner'' with George a few days after Christmas.

The source added to E! Online: ''George got down to Cabo around Christmas and had a party a couple days before the new year at his home. It was an intimate dinner with close family and friends.''

It was recently claimed that Jennifer and Justin get along so well because of a quality they also value in their famous friends - humour.

A source said: ''Jen's found a man who adores her. Justin's forever telling her how beautiful she looks. He smiles when she walks into the room.''

''He's not afraid to look silly to make her laugh, either - they laugh all the time. Why do you think they're friends with people like Jimmy Kimmel?''