McGregor, currently on the mend following a knee surgery, often fills his time with Twitter-based Q&A sessions with fans. The questions range from training/fighting to shopping to life ambitions to his favorite ring girl (the Irishman is partial to Carly Baker, by the way). The tone is rarely serious.

But when one fan asked him, sexually, whether he prefers Rousey or Tate, McGregor responded, "One riidin d--k, one lickin ma toessssss." It's a line from Dr. Dre's "Let's Get High," though not everyone seemed to get the reference.

McGregor subsequently deleted the tweet and issued an apology.

He wrote: "I would like to personally apologize to both Ronda Rousey and Miesha Tate. This morning I quoted a song on Twitter in an attempt to make a joke, which I now I see was totally unacceptable and offensive. I have infinite respect for Miesha and Ronda as individuals and as athletes. I have always been a big fan of women's MMA and the incredible talented athletes that compete in the sport. I regret making this offensive comment and I sincerely apologize to anyone whom I offended, but especially Ronda and Miesha."

It's probably a safe bet that his management team or the UFC helped craft the apology. But at least from one of the female fighting notables, there were no hard feelings.

As Tate tweeted in response to McGregor: "its all good, appreciate the apology but I knew you were just joking!"