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Between the HiddleSwift conspiracy theories and the cheating rumors Calvin Harris' new song "Ole" kicked up, blame for the end of Taylor Swift and Calvin Harris' relationship seems to keep landing squarely on Taylor's shoulders.

But what if she turned to Tom Hiddleston because Calvin did something he shouldn't have?

A new report from TMZ claims things fell apart between the Scottish DJ and his girlfriend of 15 months because he failed to give her due credit for allegedly writing one of his biggest hits.

The website cites "an early fan rumor" as its first clue that Taylor penned Calvin and Rihanna's "This Is What You Came For," which has been hanging around the top of Billboard's Hot 100 and EDM charts pretty much since its April 29 release.

According to TMZ, Taylor initially sang the track as an iPhone demo on the piano and sent it to Calvin, who loved it. The pair then reportedly recorded a proper studio demo together, but decided news of a collaboration between them "would overshadow" the potential success of the song.

Instead, Taylor published it under the name Nils Sjoberg but kept the rights while Calvin recorded it with Rihanna and welcomed the subsequent positive reception.

The day the song dropped, TMZ reports, Ryan Seacrest asked Calvin on his radio show, "Will you do a collaboration with your girlfriend?"

Calvin hewed to the party line they purportedly agreed on, telling Ryan, "You know we haven't even spoken about it. I can't see it happening though."

Despite their decision about what to tell the public, Taylor reportedly thought negating the possibility of a collaboration was hurtful, disrespectful and she believed her then-boyfriend "took it too far."

That "the breaking point in the relationship," as one source called the dispute, came shortly before the Met Gala in early May -- yep, the same gala where that video of Taylor dancing with Tom surfaced and went viral.

The actor later explained to the press association, "I was [at] a table with Taylor Swift, and The Weeknd was playing, and she said, 'The thing about these parties is nobody gets up to dance.' She, as a musician, was like, 'We've got to dance for The Weeknd.' So we got up and danced."

By mid-June, they were smooching on beaches, flying around the world together and meeting one another's parents.

According to TMZ, Taylor has no intention of barring Calvin from performing "This Is What You Came For," though she could since she owns the publishing rights. The gossip site's sources say they wanted to clear the air about what really happened because "they're sick of Calvin trashing Taylor and feel he should be thanking her for quietly giving him a smash hit."

No word, as of yet, from Taylor's rep regarding the allegations.