Samantha Cameron has revealed how she helped make up husband David's mind on gay marriage.
He says she often provided him with the "40,000-foot view" as he wrestled with the details of big decision - such as whether to press ahead with full equality on gay marriage.
Appearing together on ITV's This Morning show, the couple discussed their time in No.10 and Samantha told how, working in the fashion industry, had given her an insight into the lives of many gay friends.
She told Phil and Holly that as a parent, she wanted to make it as easy as possible for one of her children come out.
The former prime minister spoke of how he took some time to realise what it was that was needed on gay marriage.
"I was fiddling around with changes to try and make things more equal and Samantha was the one saying it doesn't undermine our marriage, why not do the full thing...," he said.
"I took a journey to get there... took a while to get to the position of what we really needed was full equality."
Phil asked whether it was his wife who had pushed him towards that decision.
She said: "I work in the fashion industry, a lot of my friends are gay, some of whom found it easy to come out to their parents, others took a long time.
"If one of my children were gay, I would hate that [feeling troubled about coming out to me], so as a parent, if there's anything you can do to make that as easy as possible in someone's life, that is important... I strongly felt that being able to marry was one of those things that could make a change."
Mr Cameron once again apologised for what has happened since the referendum but again insisted he was right to put the issue of Europe to the people of Britain.
That they rejected his campaign, he said, was deeply disappointing.
"I'm deeply sorry about what has happened since and the hiatus that we're in and I hope we can get out of it soon," he said.
"If people in parliament had voted for the deal that Theresa May had put together we would have 'Brexited' by now and perhaps we would be in a position of greater certainty."
He was asked about 'humming' as he made his way back to Number 10 after announcing he was standing down as prime minister within hours of the result - seen by many as ducking his responsibilities.
He said the "tuneless hum" was to calm himself as he feared the door to No.10 would not open as he got there.
"I'd had a few experiences of walking back to the No.10 door and it not opening and I just thought with everything that's happened, with all that's going on, with the fact the leadership election's collapsed, I'm going to be out in just days, and that door is just not going to open!
"I was trying to calm myself with that totally out of tune hum. I was in no way happy to leave."
In a moment of farce while discussing the fallout with good friend Michael Gove over the Brexit bus claims, Mr Cameron said he joined many others in shouting at the TV - only he misspoke and accidentally swore, causing Phil and Holly to dissolve into laughter.