Just when you thought Taylor Swift’s breakup with DJ Calvin Harris was amicable and so last month, things have gone south Hiddleswiftly.

The former couple apparently mixed business with pleasure and the result while catchy, isn’t playing out pretty. A representative of Swift said the pop star wrote the song “This Is What You Came For,” under the pseudonym,”Nils Sjoberg.” The hit, recorded by Harris and Rihanna, has been at the top of the charts all summer.

Swift’s contribution, of course, was not news to Harris, who one would assume was there when the collaboration happened. But he quickly launched into live-stream-of-conscious mode about the reveal in a series of tweets. Though initially complimenting Swift as an “amazing lyric writer” and saying his ex “smashed it as usual,” Harris was not pleased that sole credit was going to one of the most successful songwriters of all time.

https://twitter.com/CalvinHarris/status/753256456711843840

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

https://twitter.com/CalvinHarris/status/753257779775668224

What Harris tweeted next reads slightly bitter ex-boyfriend.

“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 added, referring to Swift’s relationship with actor Tom Hiddleston. “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.”

https://twitter.com/CalvinHarris/status/753259873035399168

Swift is no stranger to social media spats, previously exchanging words with Nicki Minaj and Katy Perry.

Harris concludes by appearing to address Swift directly, “Please focus on the positive aspects of YOUR life because you’ve earned a great one.”

It seems Taylor Swift already mixing business with pleasure already. Let’s just hope she and Hiddleston keep their collaborations on the dance floor and out of the studio. However, the singer’s romantic getaway with her new beau has been interrupted by a furious spat with her former flame, which is being played out across social media.

Taylor split from DJ boyfriend Calvin Harris, 32, five weeks ago following a 15-month romance, shortly after she was spotted partying with Tom at the Met gala.
Although, it has since been reported the couple’s relationship didn’t end because of the dance floor dalliance but may have ended after Taylor penned Calvin’s recent hit This is What You Came For, which became a sore point for them.