The two young actors dated from 2002 to 2011 and kept things very low-key, including their sudden split, but it looks like Mila is finally ready to talk about what went down and it all sounds pretty traumatic.
In an interview for her friend Dax Shepherd's podcast, Armchair Expert, the 35-year-old said she blames herself for their "horrible, horrible" breakup.
When Shepard asked Mila whether she'd "forgiven herself" yet for what went down, she responded: "You know, it's been so long like I feel like enough time has gone by. I think enough mutual friends have been like, everybody kind of forgave everybody for what went down."
Everyone makes mistakes when they're young, and for evidence of just how young Mila and Macaulay were when they dated, here's a shot of them in their dating heyday (aka 2004):
Kudos to Mila though, it takes a mature, empathetic person to recognise their mistakes and talk about them publicly.
Thankfully, both parties have moved on and are happily in new relationships.
Kunis married her That '70s Show co-star Ashton Kutcher in 2015 and they have two kids together — daughter Wyatt Isabelle, 3, and son Dimitri Portwood, 19 months.
Macaulay, meanwhile, has been dating Disney actress Brenda Song since mid-2017.