Courteney Cox Lookin' Fab at 55 ... Back in Mexico with Jen for Bday Fun

Courteney Cox is back in Mexico with Jennifer Aniston and her gal pals, and judging by her relaxed appearance ... getting there was a lot easier this time than the last girls getaway.

The "Cougar Town" star splashed in the waves on the beach in Cabo San Lucas Wednesday as she celebrated her 55th birthday with some of her best friends ... including her "Friends" costar.

The other ladies enjoying fun in the sun include actress Mary McCormack, Kristin Hahn, and Jason Bateman's wife, Amanda Anka.

It's unclear if Jimmy Kimmel's wife, Molly, made this trip, but you'll recall back in February ... she was with Jen, Courteney and Amanda when they had to make an emergency landing on the way to Cabo to celebrate Aniston's big 5-0.

Thankfully, there was no such scare that we know of for Cox's bday gathering ... just nothin' but a good time.

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