Lions safety Brian Branch has built quite the reputation early in his career, racking up over $100,000 in fines across his first three NFL seasons. Earlier this year alone, he lost $23,186 due to penalties.

He’s now facing the possibility of another fine — or even a suspension — following his actions at the end of Detroit’s loss to Kansas City on Sunday night.

After Patrick Mahomes took a final kneel to seal the victory, NBC’s broadcast showed Branch crossing the line of scrimmage and declining to shake Mahomes’ hand. Moments later, Branch and receiver JuJu Smith-Schuster appeared to exchange words before Branch slapped Smith-Schuster across the face.

That’s when Chiefs running back Isiah Pacheco stepped in, grabbing Branch and pulling him away from Smith-Schuster. But that only escalated the situation, as players from both sides rushed in to break things up. Branch seemed to throw at least one more punch before the skirmish ended.

“We play the game between the whistles,” Mahomes told NBC’s Melissa Stark after the win. “They can handle all that extra stuff how they want, but we just came out and executed. We’ll keep this momentum rolling.”

Branch entered Sunday’s matchup listed as questionable with an ankle issue but still managed to record seven total tackles.

The league will now review the situation and determine what kind of punishment Branch will receive.