Shaq -- WATCH THIS GUY GET KICKED IN THE NUTS ... That's How We Roll At LSU

Shaquille O'Neal hit up a famous college bar at LSU last night ... and watched some of the college kids kick each other in the balls ... GOOD TIMES!!!

Shaq rolled into Reggie's in Baton Rouge -- one of the storied bars in Tigerland (the nickname for the bar scene right off campus).

At some point in the evening, Shaq observed some bar patrons making a bet with each other -- one side lost -- and the penalty was a foot to the groin.

So, being the responsible journalist that he is, Shaq recorded the moment of truth ... and posted it to his Instagram page.