It's a battle of the exes!
Shortly after it was confirmed that Taylor Swift co-wrote Calvin Harris and Rihanna's hit song "This Is What You Came For," Harris went on a Twitter rant about his ex.
Harris started his tweets by saying, "And she sings on a little bit of it too Amazing lyric writer and she smashed it as usual. I wrote the music, produced the song, arranged it and cut the vocals though. And initially she wanted it kept secret, hence the pseudonym."
Swift's rep told E! News on Wednesday that she wrote the song "under the pseudonym Nils Sjoberg."
After praising Swift's writing skills, Harris then wrote, "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."
Harris even brought up Swift's new relationship with actor Tom Hiddleston.
"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," Harris tweeted. "I know you're off tour and you need someone new to try and bury like Katy ETC but I'm not that guy, sorry. I won't allow it. Please focus on the positive aspects of YOUR life because you've earned a great one."
Harris ended his tweets by saying, "God bless everyone have a beautiful day."
Watch the E! News video above to get the latest details on the feuding exes!