Conor McGregor showed his true colours following Sunday's gruesome loss to Dustin Poirier at the UFC 264 main event, once again dragging his opponent's wife into the feud.
Late in the first round of their Trilogy bout at Las Vegas' T- Mobile Arena, the Irishman stepped back and his leg snapped and collapsed under him.
Although he survived until the end of the round, McGregor's leg was horrifically damaged and the fight was stopped.
Ever defiant, he screamed at officials to ensure the result was ruled a doctor's stoppage and then produced an ugly outburst when he was interviewed by Joe Rogan while sitting against the cage post-fight.
The Notorious couldn't resist firing one final sledge at his American rival, who had dominated the lightweight contest.
"I was boxing the bleedin' head off him, kicking the bleedin' leg off him. Usual s***e, dive to close the distance," McGregor yelled.
"This is not over. I have to take this outside with him, it's on," McGregor continued.
"There was no check. There was not one of them was a check. Your wife is in my DM's.
"Hey baby, hit me back up and I'll chat to you later on. We'll be having an afterparty at the Wynn nightclub baby."
Poirier's wife was spotted showing McGregor her middle finger during the explosive spiel.
Earlier this week, McGregor shared on Twitter what appeared to be a screenshot of Jolie Poirier's direct message request.
In response, Dustin Poirier bluntly told McGregor: "Shut your b***h a**e.
"I can take even the trash – there's no holds barred on the trash talk. But murder's something you don't clown around on. There's no coming back from that.
"This guy was saying he's going to murder me and all kinds of stuff, he's going to kill me, I'm going to leave here in a coffin. You don't talk like that to people man.
"Karma's not a b***h, she's a mirror, and this guy's said the wrong s**t and I've been busting my ass. Sometimes these things happens. Naw, I beat the guy."
Poirier also accused McGregor of pushing his fingers inside his gloves while they were grappling and said he was trying to alert referee Herb Dean to the cheating.
"This guy's a dirtbag, man," he said.
But Poirier showed his class by adding: "I hope this guy gets home safe to his beautiful family, you know."
Speaking to reporters after the fight, Poirier said that McGregor had taken things too far.
"We are going to fight again, whether it's in the octagon or the sidewalk."
McGregor has lost three of his past four UFC fights – and four of his past seven – and now faces an uncertain future.
Former US President Donald Trump — a good friend of UFC boss Dana White — was in attendance at UFC 264, receiving equal amounts boos and cheers as he arrived before the co-main event between Gilbert Burns and Stephen Thompson.
American social media star Addison Rae, musician Justin Bieber and Kourtney Kardashian were also spotted in the crowd.