Giannis Antetokounmpo and Brother Dance Their Asses Off After Gym Workout

Giannis Antetokounmpo is moving on from that crushing Conference Finals loss to the Raptors by getting right back in the gym ... and dancing his ass off!!

The Greek Freak and his fellow NBA playing brother, Kostas, channeled their inner MadeinTYO for their workout cooldowns ... bustin' out the woah dance while "Chucky Cheese" blasts in the background.

If you have no idea what these kids are trying to accomplish, check out this vid.

Giannis is obviously one of the best players on the planet right now ... but that doesn't make him immune to the IG trolls ... with some people joking his moves look like a grandpa trying to be cool.

Worth noting -- if you think these guys are good hoopers, the Antetokounmpos have a younger brother, Alex ... and Giannis previously told us he's gonna be the best in the bunch!!