Charlize Theron and Sean Penn have reportedly split up after more than 18 months of dating. Theron and 39, and the 54-year-old actor, who first started dating in late 2013, are said to have secretly ended their engagement in recent weeks. A source told UsMagazine.com that the South African beauty decided that their romance was over after attending the Cannes Film Festival in France with the Milk star, who proposed during a romantic trip to Paris last November, and her adopted son Jackson, three, last month. Another source confirmed the news to PEOPLE.com and claimed the former couple, who haven't been spotted together in a number of weeks, stayed under separate roofs. The insider said Penn, who was previously married to Robin Wright and Madonna, recently pulled his Malibu mansion off the market after putting it up for sale. The pair also backed out of at least one scheduled event together before the blonde beauty flew to London to film The Huntsman. Theron recently claimed Penn was the love of her life. Speaking about working with him on their upcoming movie The Last Face, she told the June issue of Elle magazine: ''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. 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.''..