Angie Best feared history would repeat itself for her son Calum.
The 67-year-old model was devastated when Calum felling into a "fog and depression" and started abusing drugs and alcohol after his alcoholic father George Best died in 2005 and Angie was worried that Calum would never recover.
Speaking to The Daily Mail newspaper, she explained: "I thought, ‘Oh my goodness, history is going to repeat itself’ Calum needed someone to be there for him and to talk to, to help him wake up out of the fog and depression he’d been in after George’s death when he lost all hope.
"This wasn’t about fixing him, he didn’t have an addiction, but I did have to point out the different paths he could go down — one which would be a dead end and the other which would be wonderfully productive."
Although Angie – who is an ambassador for the private addiction clinic Charterhouse Clinic – loved George, she said she had to leave him for Calum’s sake and she knew their marriage was over when she mistook him for a homeless man.
She explained: "I’ll never forget the moment I knew I’d had enough, I was driving to take Calum to a check-up, it was raining, which it rarely does in California and I saw this poor befuddled, huddled, drunken-looking creature walking down the middle of the road. I thought, ‘Jesus, someone is going to hit him!’
"Then as I got closer I realised it was my husband. I thought, ‘I cannot put myself through this agony any more’. It was a moment of incredible sadness, but I knew I deserved better."
Calum, 39, has now reinvented himself as a life coach and Angie couldn’t be prouder.
She said: "No regrets. I wouldn’t change any of what happened, because now my son is a guru and I have an amazing life.
"It’s just such a shame George is not here to see it all. But that was his choice."