Charlize Theron and 'I Am Sam' actor Sean Penn have just decided to call it quits.

Us Weekly has just reported that the couple, who have been together for almost a year and a half, broke up after attending the Cannes Film Festival earlier this year. An insider says it was the 'Mad Max: Fury Road' star who broke things off.

Theron has previously admitted to Elle UK that although the Academy Award winner was "the love of her life," their relationship was still far from perfect.

"Putting aside that he's my partner, he's the love of my life; for the first time, I felt that my work was really bleeding into my life and that made it hard," the actress said. "There were moments where I was incredibly unfair to him. And moments where I felt like... he was incredibly unfair to me. But it makes you realise that no matter how complicated it gets, the priority is the relationship."

The couple had reportedly known each other for a long time before their relationship became romantic. Penn and Theron got engaged in December 2014, and although there was no ring, the two were reportedly committed to the engagement.

Penn spoke to Esquire UK about being a husband for the third time. "You say I've been married twice before, but I've been married under circumstances where I was less informed than I am today," the actor said of his past. "So I wouldn't even consider it a third marriage, I'd consider it a first marriage on its own terms if I got married again. I mean, I like the tradition. A friend of mine wrote a line, 'Without tradition, new things die.' And I don't want new things to die."

Penn has previously been married to Madonna and Robin Wright. Theron has dated actors Craig Bierko and Stuart Townsend.