Zayn Malik calls Calvin Harris a 'd---head' after DJ defends girlfriend Taylor Swift on Twitter

It's Zayn Malik v Calvin Harris after the DJ leapt to the defence of girlfriend Taylor Swift on Twitter.

The feud started when Zayn retweeted a post that negatively compared Miley Cyrus and Taylor Swift's opposing views on music streaming services and royalties.

Calvin, 31, wasn't about to let Zayn, 22, have a dig at his girlfriend over her career decisions, taking to Twitter to tell the ex-One Direction member to stay out of things he "doesn't understand". That's when things got heated.

See the tweets below...

And here's how it ended... 

Taylor, 25, has been very vocal about her position on music streaming services and artist royalties since declining to put her tunes on Spotify last year.

She also publicly refused her catalogue to Apple Music, before reversing her decision when they agreed to pay artists during the service's three-month trial period.

Zayn's ex Perrie Edwards, who he dumped last month by text message, took to the stage with Taylor and her band Little Mix just hours before this whole Twitter feud erupted. Watch below...