JOHNNY MANZIEL'S HOT FIANCEE THONGS OUT IN MIAMI

The QB hit the beach in Miami for a little fun in the sun with his fiancee , Bre Tiesi -- who turned heads in a tiny electric green bikini . .. and it was gooood .

Manziel has been training his face off for his football comeback - - recently doing sand drills with his former Cleveland Browns teammate , Joe Haden .

Of course, Bre looks amazing . .. but Johnny looks great, too -- putting back some of the muscle he had lost when he was partying his way out of the NFL.

Looks like he' s taking his comeback seriously -- but seriously, Bre Tiesi for the win.

TMZ