Sean Penn and Charlize Theron have reportedly split after nearly a year and a half together.

A source close to the matter told Us Weekly that the pair, who got together in December 2013, called it quits after their most recent trip to the Cannes Film Festival in the south of France. The source stated that the "Mad Max: Fury Road" actress was the one to break off with Sean Penn.

Before their friendship eventually blossomed into romance, Theron and Penn had known each other for a long time. In December 2014, a year into their relationship, rumors swirling around hinted that they had gotten secretly engaged during a trip to Paris.

"There's no ring, but they are committed," a source told Us Weekly at the time.

Theron recently opened up about her relationship with Penn while chatting with E! News at the CinemaCon red carpet.

She said, "It's great when you find something that's real and it's hard to keep that sacred, to keep that private in this work, but I go home at night and I close my front door and I'm a really, really happy girl."

Talking about the possibility of marrying Penn during an interview for Esquire's May 2015 issue, Theron, who is a mom three-year-old Jackson, told, "We've been friends for 20 years," she said of the actor. "He was married, I was in a long-term relationship, our spouses-not regularly, but we were in each other's lives. I think our friendship stemmed from mutual respect-more on my end, because I really didn't have a body of work 20 years ago, but my love and passion for making films-that was our common ground."

"The marriage thing is always so strange to me," Theron added.

"I love the possibility of anything, but I'm really enjoying myself and the everyday moment and how that coincides with my son and my life and my friends. I'm a very, very, very lucky girl. Very lucky. He's hot. He is hot."

The split rumors come after the two seemed totally in love than ever at the "Mad Max: Fury Road" premiere in Los Angeles in May. According to an eyewitness, Sean Penn was extremely attentive to Charlize Theron, even sneaking in kisses with the actress at the premier's after party.

In a March interview with Esquire U.K., Sean Penn said he is open to the idea of marriage again at the age of 54. The actor was previously married to Madonna (1985 to 1989), followed by a 14-year union with Robin Wright, but that too came to an end in 2010, E! News noted.

"I'm surprised to be in love," Penn accepted. "Lot of reasons. Fifty-three years old [when they got together] plus finally beginning to figure out why you haven't been happy in a single relationship? It could seem too late."

He continued, "Yes, I'd get married again. I'm in love with a woman and home is where the heart is, right?"