Skrillex and Deadmau5 have a history of not liking each other. It goes as far back as August 2015, when Deadmau5 expressed his disappointment about Skrillex, Diplo and Justin Bieber’s "Where Are Ü Now" in a string of tweets. "Made the mistake of listening to this jack u shit with Bieber assuming they at least did something cool... nope. What the fuck is this shit?” he wrote in one.
From there, the two have exchanged insults and disses on Twitter numerous times, the most recent being a confessional by Deadmau5 in December. He clarified his beef with Skrillex in a livestream, saying, "It’s not that I hate Skrillex, and I hate the shit he does… I hate that he allowed himself to be a goddamn tool for someone else. But I can’t be too much of an ass about it… he likes to do it, he’s a fucking little hippy and loves working with people, and that’s his thing. I can respect that."
Today Rolling Stone released an interview with Skrillex, in which he explained his thoughts on what Deadmau5 meant by calling him a "goddamn tool" for working with Bieber.
"If he was a real friend, he would come to me and be like, 'Yo, you shouldn't be working for Justin Bieber,' rather than blowing it up all over the Internet and going out of his way to make people feel wrong for making a choice in their life," he said.
Skrillex went on to say he actually enjoys working with the 22-year-old singer. "I'm a fan of his voice. And if you're a producer and you get an opportunity to work with someone who's the biggest artist in the world—for better or for worse—what would you say? Would you say no?"