ESPN’s new documentary, “One Night in Vegas: Tyson & Tupac” explores the friendship between the two stars, which Mike Tyson said developed after he was imprisoned for rape in 1992. Recently, the controversial former boxer admitted his biggest regret when it came to their friendship.

“He always wanted me to smoke weed with him, and I never did it and I wish I did,” he told the AP. Tyson said he always brushed off the offers because he was quitting the smoking habit. “That’s my biggest regret.”

The documentary, which aired on Tuesday chronicles Tyson’s release from jail in ’95, Pac’s imprisonment later that year, and how both built a bond because of their similar issues. “Our problem was we always had to worry about someone betraying us, our closest friends,” Tyson said.

In fact, Tyson said that because of the importance of their friendship, Shakur berated him for using another rapper’s songs for his fighting intros. “[Pac] said, ‘Don’t you ever play those fuckin’ songs again, they don’t give a fuck about you,'” Tyson remembered. “When he said that, it pierced my soul…I felt like I did something wrong.”  

Since then, Tyson has used Shakur’s songs in all of his intros. One reason Tupac attended Tyson’s fight in Las Vegas on that fateful night, is because he’d recorded a special song for the boxer’s intro.

“I felt extremely guilty because I felt if he didn’t come to this fight, that would have never have happened. It’s just so crazy that we had talked every day for a week.” Although both controversial figures fell in and out of grace under the eye of the media, it is precisely this that allowed Tyson to understand Tupac.

“He was probably a misguided warrior. He had a heart as big as the planet,” Tyson said. “He had so much love and compassion and you couldn’t even see it under his rage…I’m glad to be a part of his life and to have known him.”