Ding ding ding!! Calvin Harris has thrown himself into the ring, unleashing an epic rant aimed at ex Taylor Swift on Twitter.

The Scottish DJ, 32, took to the social media site Wednesday, accusing his one-time love of breeding “bad blood,” after her rep revealed that Swift was the wordsmith behind his hit song “This Is What Your Came For,” writing under the pseudonym of Nils Sjöberg.

“I know you’re off tour and you need someone new to try and bury like Katy [Perry] ETC but I’m not that guy, sorry. I won’t allow it,” Harris tweeted, in a reference to the long-standing feud between Swift and Perry, which inspired Swift’s hit, “Bad Blood.”

The tone of the music producer’s tweets started off somewhat good-humored — Harris initially tweeted praise for his ex, in a post linking to E! News article which detailed Swift’s role in creating the song. “And she sings on a little bit of it too,” he tweeted. “Amazing lyric writer and she smashed it as usual.”

Things escalated rather quickly after that, however, as Twitter users witnessed Calvin’s anger rise before their eyes.

First he was defensive: “I wrote the music, produced the song, arranged it and cut the vocals though. And initially she wanted it kept secret, hence the pseudonym.”

Then poor Cal got sad: “Hurtful to me at this point that her and her team would go so far out of their way to try and make ME look bad at this stage though.”

Then, he got nasty: “I figure if you’re happy in your new relationship you should focus on that instead of trying to tear your ex bf down for something to do.”

He wound down toward the end: “Please focus on the positive aspects of YOUR life because you’ve earned a great one,” signing off from his spree with “God bless everyone have a beautiful day.”

Can someone please wake up Taylor and Tom Hiddleston, who are most liking sleeping in Australia? We’ll heat up the popcorn.