Well, this is one way for the Knicks to celebrate a big win.
Josh Hart gave Jalen Brunson a big thumbs up on his NBA Cup championship performance on Tuesday ... quite literally -- 'cause he put his digit in firmly in his ass!!
The wild moment happened as New York partied on stage at the T-Mobile Arena in Las Vegas after defeating the San Antonio Spurs, 124-113.
Launch Gallery Launch Gallery GettyWhen Karl-Anthony Towns lifted the NBA Cup trophy, Brunson -- the MVP of the game -- turned to help, unknowingly leaving his back perfectly exposed to his mischievous buddy.