The 'Strip That Down' singer - who recently split from Cheryl after a two-and-a-half year romance - was furious when he saw Jean-Bernard Fernandez-Versini partying with pals at the same nightclub as him in Monaco recently and he launched into a foul-mouthed tirade.
A source told The Sun: ''The whole night he was standing behind JB looking to fight him. He was stood there with his arms crossed and he kept pointing at JB - nobody could understand what he wanted.
''And JB was just ignoring him because he was like: 'I'm 35 years old, he's a 20-year-old kid. I don't want to fight this kid in Monaco - it's supposed to be a smart place'.
''In the toilets, one of JB's friends turned round to see Liam looking at him and it flared up. He said: 'What the f**k are you looking at?' and Liam said 'Listen, your friend JB is a f*****g ****.' Security stopped things escalating but as he left he looked at him and said: 'I will f**k you up.' It was all a bit embarrassing.''
JB was annoyed that Liam went after his friend and confronted the 24-year-old singer about it at the club Twiga but Liam had no response.
And restaurateur JB later told pals that Liam was only a kid who needed a hug.
This is the second time Liam and Jean-Bernard have clashed since the One Direction star split from Cheryl, 35, the mother of his 15-month-old son Bear, in July.
The pair narrowly avoided an altercation at the Chiltern Firehouse earlier this month.
A source said at the time: ''Liam was worse for wear. He was goading JB but JB said he was not going to get involved with a 'little 24 year old boy'.
''He's not one to cause a fuss and knew Liam was only acting like that because was a little tipsy.''
However, JB later lashed out at Liam, calling him a ''little man'' who was wrong for her.
JB is also believed to have told friends that he wants Cheryl back.
A source said: ''JB always knew Liam and Cheryl wouldn't last - she is 10 years older.
''If Cheryl walked back into his life he would give their relationship another go.
''Marriage has always been sacred for JB. He loved Cheryl deeply.
''She was the only family he had. He was upset they finished and always wanted to protect her and still does.''
Cheryl and Jean-Bernard married in a secret ceremony in Mustique in July 2014 after three months of dating and split up 18 months later.
RYD, aka North London producer Ryan Downie, is set to release his self-titled debut album under that moniker on 18th January.
It's been almost three years since the release of their second album The Ride and now Catfish and the Bottlemen return with the video for their...
Everyone's favourite pop rock band return with an animated lyric video for their new single 'Bad Liar'. Following 'Machine', the single features on...
Janelle Monáe parties and drives with her girl squad in the video for her latest single 'Crazy, Classic, Life', taken from her album 'Dirty...
To coincide with the new BBC mini-series adaptation of leporine epic Watership Down, Sam Smith has unveiled a new single entitled 'Fire on Fire'.
Professor Green and Rag'n'Bone Man have teamed up for a heart-wrenching video for their single 'Photographs'.
Tristan Corrigan on the difficulties of making music within a genre that is so popular.
From 'Happy' to 'Banana Pancakes', these are soaked in positivity.
Filmmaker Spurlock (Super Size Me) is known for his investigative wit, but there's none of...
British pop heartthrobs One Direction became a worldwide sensation when they were thrust together on...
Niall Horan, Zayn Malik, Liam Payne, Harry Styles and Louis Tomlinson may make up the...
They're the biggest boyband in the world since coming third in the seventh series of...