Ariel Winter My Girls Are 18 And Lovin' It!!

2/1/2016 7:04 AM PST

Ariel Winter enjoyed the spoils of turning 18 ... partying at an L.A. hot spot and showing off her body -- so we're guessing her BF had a good time too.

The "Modern Family" star and Laurent Gaudette hit up The Nice Guy Sunday night where she celebrated her recent 18th birthday in an outfit that was long on legs, and heavy on cleavage.

It was a chilly night in L.A. -- 45 degrees -- but Winter's clearly ready for summer.