DeMario Jackson's Ex Put A Bow On Her Assests!!!

Lexi Thexton's message to DeMario Jackson for ditching her to go on "The Bachelorette?" -- the pose says it all ... ya assed out on getting this!!!

Lexi showed off her buns in a pink bikini in Santa Monica ... and she's as hot as the sand.
You'll recall Rachel Lindsay infamously booted DeMario when Lexi made a surprise 'Bachelorette' appearance to confront him for going on the show even though, according to her, they were still an item. Lexi's single now ... but with those buns, probably not for long.