Jennifer Aniston - Beach Reading with Justin Theroux

Jennifer Aniston shows off her flat tummy while donning a bikini during her vacation with shirtless fiance Justin Theroux on Sunday (December 31) in Cabo San Lucas, Mexico. Later in the day, the 43-year-old actress was seen enjoying some leisure time while reading a book in a different bikini. On the same day, Justin and Jennifer were spotted showing each other affection while wrapping their arms around each other. Jennifer and Justin are currently on vacation with their celebrity pals John Krasinski, his wife Emily Blunt, Jimmy Kimmel, and his fiancee Molly McNearney. Earlier in the week, Jimmy, John, and Molly were seen paddle boarding in the ocean.