Zayn Malik, Calvin Harris clash on Twitter

Taylor Swift caused the heated exchange of words.

Calvin Harris and Zayn Malik were involved in a Twitter spat over Taylor Swift.
The online tiff began when Malik, 22, retweeted a post critical of Swift's refusal to stream her music on website Spotify on Monday.
Harris, a 31-year-old Scottish DJ, stepped in to defend Swift, who is his girlfriend, thus initiating a war of words on the micro-blogging website, reports dailymail.co.uk.
Malik retweeted a post comparing Swift's refusal to stream her music for free with a quote from Miley Cyrus saying she doesn't care about money. "The difference is astounding," wrote the poster.
Harris quickly jumped to Swift's defense, writing: "You've made your money? Cool... f*** the 99 percent of musicians who depend on these services to survive, right? Yeah f*** em.
"If you don't get what it means when a successful artist uses their celebrity to benefit every other musician and songwriter in the industry... then stay out of my f***ing mentions."
Malik then hit back at Harris. "@CalvinHarris ha you just made an absolute fool of yourself mate", he tweeted, adding that it had been a general statement, not a dig at Swift. "@CalvinHarris you clearly don't understand what I just said either... So I suggest you calm your knickers before them dentures fall out," he added.
Both musicians have since deleted many of the offensive posts, although Harris did end the exchange by telling Malik it was nothing personal, adding "best of luck, you've got a great voice".