Just a few weeks after Zayn quit 1D, there were online fireworks between him and former bandmate Louis on Wednesday evening (6 May).
Replace this . pic.twitter.com/Dis0Tfd7cz— Naughty Boy (@NaughtyBoyMusic) May 6, 2015
It all started when Zayn's new collaborator Naughty Boy posted a picture of himself and Zayn in the recording studio with the caption: "Replace this."
Zayn retweeted it.
Louis then got involved by tweeting: "Remember when you were 12 and you used to think those Mac filters for your pictures were cool. Haha! Some people still do HA!"
Presuming the jibe was about him, Zayn replied directly to Louis saying: "Remember when you had a life and stopped making bitchy comments about mine?"
That comment was retweeted more than 200,000 times.
Louis didn't respond to Zayn – but did get into a clash with Naughty Boy after the latter tweeted at him: "And some people can't even sing… but who's complaining when there's autotune, eh?"
Louis' response? "Jesus, forgot you were such an in demand producer. How does it feel to be riding on the back of someone else's career?"
Naughty Boy replied: "Yeah, how does it feel mate? You've been doing that for the last five years. I've got Emeli Sande and Sam Smith on my CV."
Louis said: "Good for you! Well done! I think we've done alright in terms of sales and I've happened to write on most. Keep trying!"
Oh dear… what will happen next?
This morning, Zayn took to Twitter to clarify what he had been saying and question why people were sending him nasty messages.
"Don't know why I'm being attacked for defending myself, people got it twisted! I love my fans?! Every single one of you x."
Watch the public - and some celebs! - react to Zayn's exit from 1D: