Machine Gun Kelly played Kentucky's Louder Than Life festival over the weekend - and was relentlessly booed by Slipknot fans.
The controversial pop-punk artist is waging a war of words with Slipknot, after falling out with Corey Taylor.
The two were meant to collaborate, but it has since descended into barbed remarks onstage and in the press.
With Machine Gun Kelly's insults at Riot Fest going viral, he hit the stage at Louder Than Life in Louisville, Kentucky with a point to prove.
However the audience seemed to consist primarily of Slipknot fans - who spent the duration of his set jeering him.
Attempting to quell the crowd, Machine Gun Kelly says: "I see you dude, I see you mad as fuck in your weird fucking outfit. I'm here for the same shit you're here for [the music], so it's all good. Clearly, I'm not going nowhere, so just enjoy."
Bizarrely, at one point the pop-punk artist pulls out a lightsaber: "You keep fuckin' with me, homie? Trained Jedi, bitch!" Watch footage of the set below.