We all know that Justin Bieber likes to pick fights with photographers, reporters and Orlando Bloom, but he may have bitten off way more than he can chew by pissing off UFC champ and reigning Biggest Badass on the Planet, Ronda Rousey.
Rousey spoke with Cosmo recently, and she told an all-too-familiar tale of Bieber douchery.
"Justin Bieber was actually really rude to my little sister at the Cannes Film Festival," Rousey began.
"My little sister is really hard to impress. She didn't really care about anyone at the Cannes Film Festival, but I wanted to spend some time with her.
"Justin Bieber was over there, taking some pictures with some ladies, and she suddenly got really excited. She was like, 'Do you think he would wanna take a picture with me?
"I was like, 'Sure, Julia. Don't worry about it...I walked over there and he turned to me and he goes, 'I've already taken a billion pictures today.' And I said, 'Yeah, but - she's the only 16-year old girl at the whole party.
"I only got 'yeah, but' out, and he goes, 'A billion!' and he walks off and totally snubs my little sister. She looked at me, and she's like on the verge of tears and she goes, 'I'm no longer a Belieber.
"Yeah, I don't think I'd wanna hang out with him," Rousey added. "I'm not a Belieber. I was, but I'm not anymore."
Interestingly, Bieber is friends with Floyd Mayweather, who's also but taken down a peg by Ronda in the past.
When Floyd boasted about his superior wealth (as he does constantly), Rousey reminded the world that he's an illiterate woman-beater.
So far Ronda is dominating her bout against The Money Team!