Celtics’ Jaylen Brown calls Giannis Antetokounmpo “a kid” after an offensive foul and improper handshake.

Despite Giannis Antetokounmpo’s 43 points and 13 rebounds, the Milwaukee Bucks lost 113-107 to the Boston Celtics on Sunday.

But after the game, Celtics players expressed their anger at Antetokounmpo and his behavior on the court. Jaylen Brown was particularly outspoken about his feelings towards the Bucks star.

“Giannis is a kid,” Brown said. via NBC Sports Boston. “I’m just focused on helping my team win. And we managed to do that tonight.”

If Brown’s irritation was about Antetokounmpo’s fake handshake, something you might see a fourth-grader do on the playground, then it seems rather humorless. However, he was asked about an offensive foul Antetokounmpo committed on the field before the game was changed, and that more explains Brown’s reaction.

On the play in question, Antetokounmpo swung his left elbow around and hit Brown in the side of the head as he attempted a shot into the lane.

On the way back to the field, Antetokounmpo tried to slap Brown’s hand or shake his hand as if to say, “No hard feelings.” Brown was about to reluctantly acknowledge the gesture. But when Antetokounmpo pulled his hand away to run his hands through his hair, it showed insincerity.

If Brown was already upset about being elbowed in the head, the wrong handshake certainly upset him. He effectively put Antetokounmpo on notice with a hard foul in the fourth quarter, called Flagrant 1.

When asked if Brown called him a child, Antetokounmpo responded with surprise.

“Oh, that’s what he said?” he replied. “Damned.”

That wasn’t the only controversial play involving Antetokounmpo on Sunday. Early in the game, he stuck out his left leg while Jayson Tatum shot a three-pointer. That caused Tatum to twist his ankle as he landed on Antetokounmpo’s foot.

Antetokounmpo was not warned for a landing spot foul, which Celtics coach Joe Mazzulla complained about after the game.

“This is ridiculous,” Mazzulla told reporters. “I can’t miss this. I can’t miss this.”

Understandably, Tatum was upset about not calling and also about his sore ankle.

Tatum finished the game with 31 points and 13 rebounds as his team also earned the victory. A game between the Celtics and Bucks seemed like a potential Eastern Conference playoff matchup earlier this season. But due to Milwaukee’s problems, a bid for the postseason appears questionable at this point. But there is still a lot of the season left to play.

The Celtics and Bucks play again in Boston on December 5th.