Charlize Theron and Sean Penn are getting quite serious that the South African beauty is already thinking about marriage.

The "Mad Max: Fury Road" graces the latest cover for Esquire magazine and in the accompanying interview, she talked about her "hot" boyfriend, Sean Penn.

"We've been friends for 20 years. He was married, I was in a long-term relationship, our spouses-not regularly, but we were in each other's lives," she said. "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."

Also, she loves that Sean Penn can carry a conversation about relevant topics outside of the movie industry.

"That's sometimes hard to find among friends here, and that's where our friendship really blossomed," the 39-year-old actress said. "A lot of people want to tell you the answer to solving all of Africa's problems from what they've seen on CNN. Sean is not that guy. When he started working in Haiti and I started working on the AIDS front in South Africa, we spent a lot of time talking about those worlds."

Still, Charlize Theron couldn't have imagine calling Sean Penn as a boyfriend.

"I think that for both of us there was never a moment where we thought that this-what we have today-would ever even be a possibility. Ever, ever, ever. I think we're both finding ourselves at this moment in our lives kind of shocked. Both of us," she said.

"Just when you think you know how things are supposed to go down, life just kicks you in the ass and guess what? You don't have a clue," Charlize Theron added.

Charlize Theron and Sean Penn were reportedly engaged in November last year and a report from Us Weekly claimed that the 54-year-old actor wants to take his relationship with Charlize Theron to another level.

"Sean always knew that to truly earn a place in Charlize's heart, connecting with Jackson was one of the most important parts," the source said. "There is still talk of adopting again and giving Jackson a brother or a sister."