An already competitive game between Boston and Milwaukee took a further turn Monday, after a seemingly innocuous prank courtesy of former MVP Giannis Antetokounmpo.

During the game, Antetokounmpo appeared to reach out to Boston’s Jaylen Brown, offering a handshake, before pulling away to instead rub his hair once Brown returned the gesture.

‘Giannis is a child’: Feud brews between Boston Celtics and Milwaukee Bucks

What seemed like a typical case of joking around soon took a turn, with Brown taking exception to the move.

Feud brews between Celtics and Bucks after prank

After the game, the reigning Finals MVP Brown was asked his opinion on Antetokounmpo’s antics, delivering a frosty answer.

“Giannis is a child,” Brown said.

“I’m just focused on helping my team get a win. And that’s what we did tonight.”

Brown also appeared to shake his head following the encounter on the court, a reaction that left Antetokounmpo surprised.

“We always joke around with the flow of the game,” Antetokounmpo said.

“It’s something that I do to my kids, I play around.

“This is who I am. I play the game with fun, joy.”

It was Brown who had the last laugh, however, as the Celtics took down the Bucks 113-107, as the Bucks sunk to a stunning 2-8 record to start the season.