Dwyane Wade -- I'm Taking Gabrielle to 'Fifty Shades' ... I Wanna Learn Something!!

Dwyane Wade could be trading basketballs for Ben Wa balls -- the NBA star tells TMZ Sports he's taking Gabrielle Union to see "Fifty Shades" this weekend because "I wanna learn something!!"

This clip is awesome ... Wade (who's out in NYC for NBA All-Star Weekend) told us he's not gonna let his new wife drag him to see the movie -- instead, he proclaimed, "I'm taking HER!"

"I wanna learn something," Wade said ... "I'm married! You gotta keep it up!"

#LearnTheSafeWord