Patrick Mahomes throws helmet during sideline tantrum after losing to Bills

The Kansas City Chiefs lost their third game in four weeks and Patrick Mahomes is not happy about it at all.

The Chiefs quarterback lost it on the sideline after losing 20-17 to the Buffalo Bills at Arrowhead Stadium on Sunday. He had to be held back by teammates while tearing into the refs. Then he took his frustrations out on his helmet, slamming it to the ground in anger.

To say that he's frustrated would be an understatement.

Watch: Patrick Mahomes throws tantrum after Chiefs lose to Bills

What got Mahomes so heated? Besides losing another game in frustrating fashion, Mahomes seemed to be targeting the refs. There was nothing obvious to spark his anger on the final play of the game — the Chiefs failed to convert a fourth-and-15 — so perhaps he was still fuming over the pivotal offsides call that took a touchdown off the board.

Kadarius Toney was flagged for being lined up in the neutral zone on a play that might have won the game for the Chiefs. Mahomes hooked up with Travis Kelce over the middle of the field and then Kelce put jaws on the floor by throwing a backward pass to Toney, who ran free to the endzone. But the yellow laundry on the field negated the play.

The quarterback being angry about that moment would be understandable, but replays showed it was the right call.

Mahomes was 25-of-43 for 271 yards in the game. He threw a touchdown but also tossed an interception on the opening drive for the Chiefs.

Once again, the story of the game was wide receiver miscues. Rashee Rice lost a fumble while Toney committed the most costly penalty of the game with his offsides.

Opposite Mahomes, Josh Allen was 23-of-43 for 233 yards, a touchdown and an interception. He also ran for a score. The Bills kicked a go-ahead field goal with 1:54 remaining to ultimately win the game.