The relationship between the married couple started out as 'friends with benefits'.
Before Ashton Kutcher and Mila Kunis were a happily married couple with a daughter and another baby on the way, they just 'fooled around' as buddies.
In fact, the night they got together, Ashton intended to set Mila up with a friend. It's safe to say that didn't go as planned!
"Long story short, I didn’t leave until the next morning,” Mila told Howard Stern.
"Then we ended up having a lot of talks about how this is a huge mistake and how he needs to go and be single and how I need to go and be single. It was super private for a very long time.
"Three months later I was like, this isn’t fun anymore."
The news of Ashton and Mila's 'casual' deal will please fans who saw the pair's competing rom-com flicks about friends who sleep together, only to end up in love.
The films, No Strings Attached and Friends with Benefits, were released around the same time and addressed the same themes, but Ashton starred in the former with Mila's Black Swan co-star, Natalie Portman, while Mila fronted Friends with Benefits alongside Justin Timberlake.
Talk about irony!
Before this even, the pair were just friends - meeting for the first time on the set of That 70s Show when Mila was 14 and Ashton 19.
“I never looked at him as somebody that was good looking," Mila said. "I never looked at him as somebody that wasn’t...I just was like, here’s a guy that I’m working with for eight years and he’s really smart. And I had to do chemistry and he was better at chemistry than I was so he’d help me with my chemistry homework and when I was grounded he would drive me home."
She finally realised Ashton - a former model - was rather hunky when she ran into him at an awards show before the fateful housewarming.
"I think he, for the first time, ever took my breath away. I was like, f*ck he’s good looking," Mila confessed.
Listen to the full interview: