Why does Post Malone have tattoos of Patrick Mahomes and Travis Kelce on his body?!
Because the NFL stars kicked his ass in an epic backstage beer pong match -- and the loser had to get tats!!
It all went down after the Chiefs beat the Niners in the Super Bowl -- Mahomes and teammate Kelce were able to score some VIP tickets to Post's February concert in Kansas City.
But Mahomes told GQ before the show went on .