Lightweights Michael Chiesa and Kevin Lee Brawl During UFC Press Conference

Warning: Language in videos is NSFW.

Things got heated outside of the Octagon for two UFC lightweight contenders on Friday. 

During the UFC Summer Kickoff press event in Dallas, UFC lightweight Kevin Lee dropped the "M" word to his upcoming opponent, Michael Chiesa.

"I know his mom's got tickets," Lee said.

Chiesa immediately reacted and rushed Lee:

Both fighters were ejected from the conference, but not before Lee landed a punch on Chiesa. 

UFC light heavyweight champions Daniel Cormier and Jon Jones also got into a heated exchange backstage over Jones' mention of Cormier's kids.

Let's leave family out of it, shall we?