As Mahomes recalled in an interview with Clay Skipper of GQ, Post was in Kansas City for a concert the day the Chiefs held their Super Bowl parade and invited him and Kelce backstage. Post challenged the pair to a series of beer-pong games, which turned out to be a bad idea.
Post, who described himself to Skipper as a "pretty f------ competitive beer-pong player," fell behind quickly to the Chiefs duo. They were interrupted nine or 10 games in by Post's manager letting him know it was time to take the stage, but play continued.
Around the 14th or 15th game, Post handed Mahomes and Kelce a piece of paper to sign and said he would get their autographs tattooed on his body if they beat him again. They did, and Post followed through with his promise.
"He has a tattoo artist literally in the room," Mahomes said. "I'm like, 'Dude, you do not actually have to get a tattoo of our autographs.'"
Mahomes couldn't give an exact number on the amount of full beers he drank "because half the beers were on my clothes," though he did say it was "way over" 20.