In a new interview with Rolling Stone UK, Osbourne blamed the breakdown in his friendship with Butler on a falling out between his wife/manager Sharon and Geezer's wife/manager Gloria Butler.
"[BLACK SABBATH guitarist] Tony Iommi has been so supportive of me since my illness," Osbourne said. "Geezer Butler hasn't given me one fucking phone call. Not one fucking call.
"When his son was fucking born, I phoned him every fucking night even though we were at war with each other, BLACK SABBATH and me [after I was out of the band]. I thought, 'Fuck it, he's my mate. I'm gonna call him.' But from him, not one fucking call.
"It's sad, man," he continued. "We all grew up together, and he can't pick up the fucking phone like a man and see how I'm doing. Even [original BLACK SABBATH drummer] Bill Ward has been in touch with me. I said some things about Bill, and I don't know why I said it, but when I came through my illness, he contacted me.
"I'm not in shock. I'm just very fucking sad that he can't just call me after all this time and say, 'How you doing?' Fucking arsehole."
Asked why he and Geezer had a falling out in the first place, Ozzy said:
"His wife and my wife had a falling out. But that's got fucking nothing to do with me. Are you really going to hide behind your wife's skirt because of that?"
Butler has responded back on Instagram:
"Rumour has it; Ozzy is upset, saying he never received my get well messages. I made 2 different attempts at getting in touch during his illnesses. My first email (8 Feb, 2019) went through his office because I didn't have Ozzy's new number to text him. Sharon responded but I didn't hear back from Ozzy.
11 months later (21 Jan, 2020), I emailed Sharon to check on Oz. That email went unanswered.
I don't want to engage in a tit for tat. Having made 2 attempts to wish Ozzy well, without a reply, I figured it best to privately keep him in my thoughts."