The Queen icon was talking to Lisa Robinson in 1984 when he said the pair fought every time they were together in a room.
Laughing with his interviewer, he slated May’s own songwriting skills – but made it clear he was only joking.
It’s a great reminder of Mercury’s sharp personality and sense of humour, and the clip has been seen 1.8 million times on YouTube since being shared three years ago.
“Every time I’m in the same room as Brian we start [fighting],” he said.
“I haven’t hit him yet but there’s still time!”
He added jovially: “He writes the kind of songs I don’t like.
“No, no, no, let’s be serious about this – he writes, I mean especially now, total extremes. He’s still into heavy metal type stuff – which is fine.”
In another interview from the same year, with Mary Turner, he spoke a little more seriously about their artistic differences.
“Brian’s got his own writing ideas and they’re very strong – to start with, anyway,” he said.
“I don’t seem to be able to get into his ideas so much, but in a way that’s quite good.
“I’d rather leave it to him – and it doesn’t mean I stay out of it altogether.”
Mercury died in 1991, and May recently completed a trip to where the icon grew up as a child, posting emotional tributes on his Instagram.
The adventure came just before May returned to touring with Queen co-star Roger Taylor on their new Rhapsody Tour, on which Adam Lambert is the vocalist.
The jaunt continues across North America until late August, before heading to Asia, Australia and New Zealand in 2020.
May recently wrote of Lambert on Instagram: “Gifted with a voice in a billion, for himself he is a passionate and unyielding perfectionist.
“Gifted to us, he is the reason that we are still alive as a functioning rock band. And still able to take on new challenges. Plus … he’s nice. That’s a big deal when you’re a touring family.
“Freddie would approve, big time.