Klay Thompson is straight up pissed over the "F*** You Draymond" chants that rained down on the Warriors on Wednesday night ... ripping Celtics fans for the vulgar words and calling Boston supporters "real classy."
While Boston was up big late in the fourth quarter of Game 3 of the NBA Finals at TD Garden, their fans let Draymond Green have it -- chanting "F*** You" over and over again at the star after the Golden State forward had ruffled feathers in Games 1 and 2 of the series.