Machine Gun Kelly is opening up about Sean Strickland after their run-in at a Power Slap event back in February … warning the UFC fighter to quit running his mouth!

The Cleveland native swung by Logan Paul‘s Impaulsive podcast to chop it up on a wide range of topics … including the disdain between Kelly and Strickland.

At a point during the conversation, the topic turned to Strickland … and it’s very evident MGK is far from a fan of the former UFC middleweight champion.

“I don’t know this guy from a crumb of bread,” he said. “I didn’t know who he was when I met him. I got hip afterward that he’s insanely racist and homophobic and just not my type of guy, so I would have never wanted to shake his hand in the first place.”

MGK wasn’t done … going on to say that Strickland is too scared to be himself.

“If you’re comfortable as yourself, you don’t care who anybody else is and how they are,” he said.

Machine Gun Kelly even offered some advice for the former UFC middleweight champion … telling him he should “Shut the f*** up!”

“Don’t speak on me anymore and live your life,” he said. “But you won’t, and I’m going to continue laughing at you because you’re a f****** idiot.”

The latest salvo comes on the heels of Strickland’s appearance on Verse Us With Eric Nicksick … where he talked about running into MGK at the Power Slap event earlier in the year. Sean also spoke about Megan Fox, MGK’s partner, and her children.