Ayda Field was worried Robbie Williams would relapse after he accidentally drunk beer.
The 'Angels' singer is a recovering alcoholic and hasn't touched booze for almost 20 years, but he and his wife were left horrified when he took a drink from a fan at his Las Vegas residency and discovered the contents.
Robbie said: "In Vegas there's this guy, and I'm singing to him and he's got this can of what looks like a soft drink.
"I said, 'Is that a soft drink?' and he went, 'Yes'. And I took a sip and it was beer."
Speaking on their podcast, 'At Home With The Williamses', Ayda added: "I had a mini crisis watching it happen, going, 'Oh my God, is this going to trigger a relapse'."
The 40-year-old actress - who has kids Teddy, seven, Charlie, five, and Coco, 15 months, with Robbie - went on to hit out at the fan for their "irresponsible" actions.
She added: "Thank God it didn't, but I was like, 'That is a really irresponsible thing to do to an alcoholic when they've asked you if it was alcohol'."
But the 'Loose Women' star admitted she realises not everyone is aware of the 45-year-old singer's addiction struggles.
She told her husband: "I have seen people put a glass of wine in front of you, so not everyone knows about the raging alcoholism."
As well as his alcohol problem, the former Take That singer has battled with his weight for many years, used to have a 40-a-day cigarette habit and previously entered rehab for an addiction to prescription drugs.
Robbie has long kicked his past habits in the head and now follows a health and fitness plan after joining WW - formerly Weight Watchers - but previously admitted if he had kept going the way he was he believes he would have ended up dead.
He said: "I knew I had to take action or I was going to die.
"Take it in small steps.
"You can only get bucked off the horse so many times, daily, secondly, minutely, but you just keep getting back on the horse and then your percentage of who you are, where you are and how you feel about yourself and life will get better and better but it's a hard journey."