Mila Kunis and Ashton Kutcher are the picture of a happy couple today, but she admitted that she used to think he was "crazy".
The pair met on the set of That '70s Show in 1998 when Mila was 14 and Ashton was 20, but they did not start dating until 2012 and became engaged two years later.
Mila admitted to disliking him so strongly at points during their friendship that the idea of the pair being a couple was completely off the cards, but now it has made their relationship stronger.
She told US Glamour: "There's nothing we don't know about each other because we've known each other for so long: the ugly, the bad, the good.
"We went through a period where I thought he was crazy. At the height of his career, I was like, 'Ugh, I don't like you. I don't even know you anymore. You think you're such hot s***'... Full friendship breakups.
"And then we'd get back together and be like, 'Oh, sorry. I didn't mean to overreact'."
She added that now "it truly is being married to your best friend. That's a cliche; it's cheesy. But it's true".
Both being actors has made for big downside for those who know little white lies are what keep a relationship going.
She admitted: "I literally can't lie to him. He can call me out on everything, and I can do the same, because there's nothing about the other person's face that we don't know."
The pair share one-year-old daughter Wyatt Isabelle and Mila is happily taking a break from acting to enjoy motherhood as she expects their second.
She said: "I would get a call with an offer, I wouldn't even flinch.
"I wasn't ready to go back. I was so happy saying no that I knew it was the right decision."
Mila came with her parents as refugees from the Ukraine to America at the age of seven and was outspoken against Donald Trump's anti-immigration rhetoric.
She said: "We came here on a religious-refugee visa, and I'm not going to blow this country up. I'm clearly paying taxes. I'm not taking anything away...It saddens me how much fear we've instilled in ourselves."
Speaking about Trump's "really great sound bite" that he would build a wall between the US and Mexico, she lamented: "Nobody should be mad at him; we did it to ourselves."
Read the full interview in this month's US Glamour.