Tensions are boiling over and this head coach had to be restrained from going after another coach

It's never a good thing when coaches are mixing it up on the sidelines.

Videos by FanBuzz

And that's exactly what happened Sunday during the Houston Texans-Detroit Lions game when Houston had only 10 men on the field and head coach Bill O'Brien had to burn a timeout. Cameras showed an irate O'Brien ripping into his special teams coach, while being restrained by other coaches.

The Texans ended up winning the game to move to 5-3 and remain in first place in the AFC South.