By Sarah Bull and Owen Tonks
Things turned personal on The X Factor on Saturday night, when the normally charming Gary Barlow accused his fellow judge Tulisa of having 'fag ash breath'.
It came to a head after Tulisa criticised Gary for the song he had chosen for his act Christopher Maloney, saying to him: 'Gary, how many of these eighties classics are you going to let him keep destroying?'
Gary, who had clearly been contemplating his response while Tulisa spoke, then said: ''I don't know what's offended me more - what you said or the fag ash breath!'
Scroll down for video of the row
And Tulisa was as shocked as everybody else by Gary's out-of-character comment, sitting there open-mouthed as she took in what he had said.
But as Dermot O'Leary spoke to Christopher following the performance, Tulisa interrupted saying: 'Just a note for Gary - lay off the red wine because I can really smell that as well.'
Later on ITV2's The Xtra Factor Barlow was asked if he had been drinking red wine and he said he had 'a little sip' in his dressing room and went on to apologise to his fellow judge.
He said: 'Can I apologise to Tulisa - I mean it. You have the freedom to be as personal as you like to me for the rest of the series - insult me.'
Tulisa told The Xtra Factor that Barlow had once said he 'loved' the smell of cigarettes because it reminded him of the days he used to smoke and Barlow agreed.
But when asked if she had accepted Gary's apology, Tulisa replied: 'No, not yet.'
The row occurred after Christopher took to the stage performing Cutting Crew's Died In Your Arms - a heartfelt performance but once which lacked the Halloween theatrics of some of the others.
Nicole said afterwards: 'That was fun, I felt like I was watching an Eighties Halloween pop opera but I want to just to give you a hug. Good job on the vocals, I loved how you ended on the falsetto.'
Louis said: 'You haven't been in the bottom two yet but we are looking for a future recording star but I think you are more of a cabaret star.'
And while Gary may have shown his harsh side to N-Dubz singer Tulisa, he wasn't quite as cruel with his comments to contestant Rylan Clark.
Gary hasn't warmed to the aspiring pop star in recent weeks but he made an effort to give the entertainer some constructive criticism following his performance.
The Take That star may be changing his opinion of Rylan after his former bandmate Robbie Williams showed his support for Rylan during last week's show and offered up his advice during a masterclass in London on Wednesday.
And Rylan, who turned 24 this week, was pleased with the tuition he received from Robbie - the hopeful took to Twitter to express his delight following the session.
He wrote: 'Such an amazing birthday present @robbiewilliams thank you for everything you said. See you again Sunday x'