Sofia Vergara — Looks Like an ENGAGEMENT RING!

0711_sofia_vergara_enpactoModern Family” hot mama Sofia Vergara celebrated her big 40th birthday by rocking a sexy bikini in Mexico … and flashing what is reportedly her new giant engagement ring on Tuesday.

Sofia”s on-again/off-again businessman boyfriend Nick Loeb reportedly popped the question and gave her the huge bling during their vacation with pals on the Riviera Maya this week.

Sofia — who dated Tom Cruise before the whole Katie Holmes thing — has a son from a previous marriage.