In a new interview with Esquire UK, the Milk actor says he's "in love" with Theron, and would consider their marriage his "first" despite having been previously married to both Madonna and House of Cards actress Robin Wright. Penn, 54, and Theron, 39, first stepped out together in December 2013, and reportedly got engaged this past November.
"Yeah, I'm surprised to be in love," Sean tells the men's magazine. "Lot of reasons. I’m self-proclaimed bad at mathematics but I can do two plus two: 53 years old plus finally beginning to figure out why you haven’t been happy in a single relationship? It could seem too late. But to run into somebody now who you care about is a much more passionate, deeper, truer and -- God! -- a much happier feeling. It's a lot more romantic and a lot more fulfilling to be in a relationship and to think you're a good person within it."
He says he isn't afraid to take the next step with Theron, despite two failed marriages. He chalks this up to his love for "tradition."
"Yes, I'd get married again," he stresses. "You say I've been married twice before but I've been married under circumstances where I was less informed than I am today, 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."
He admits, however, that he isn't on the best terms with Wright, to whom he was married to for 14 years. They have two children together, son Hopper, 21, and daughter Dylan, 23, a model.
"I’m very friendly with my first ex-wife," he says, referring to Madonna. "I would say that I’m on extremely good terms with the children I share with my second ex-wife."
But he's willing to take some responsibility for their less-than-friendly split.
"Initially, in a divorce, you kick and bite about the other person," he admits. "But finally you’re looking at your failures to that person, to a marriage, to a friendship, to yourself during that time as well. Because no matter what the other person was or wasn’t, for better and for worse, it really has so little to do with the growth you need to find better circumstances. Almost exclusively it has to do with your own stuff."