It's not a stretch to say that Irish mixed martial arts (MMA) fighter Conor McGregor, a big winner in his UFC match in Boston on Sunday, is one of the hottest sports stars out there at the moment.

So who’s got the tough guy’s back most of all? His long-term girlfriend Dee Devlin, a Dublin native who remembers the days when McGregor was just starting his MMA career in Ireland, fighting in front of 50 people or so. Now he’ll be competing for the UFC crown in front of thousands – many of them his traveling army from Ireland – come May in Las Vegas.

Devlin was with her man in Boston, and the fuss took them by surprise. “It’s crazy and every couple of months it goes to another level,” Devlin told an interviewer about the buzz surrounding her beau.

“When we came to Boston last time Conor was on the undercard. Now we’ve seen Conor on the side of buses and on billboards.”

Fight day is stressful enough for Dee, as the UFC isn’t for the faint of heart. “It’s definitely a day when my stomach isn’t in the best place,” she says. “I’m a ball of nerves. But once I see him just before the fight I’m fine again.”

McGregor’s life is devoted to being the king of the UFC, his girlfriend says, and that’s fine with her.

“He doesn’t shut off. It’s weird to say but he doesn’t. He doesn’t have a hobby. We have a dog that we walk, and even when we do that he’s shadow boxing along the way.”