Why would anyone want to date Sean Penn?

If you thought Charlize Theron was just the latest A-list notch on Sean Penn's bedpost, think again. "Charlize is not my girlfriend,"

Penn, 54, corrected a French reporter who asked about the relationship in February. "She's the love of my life."

The public declaration of Penn's affections surprised few in his inner circle. After 11 months of dating, the couple reportedly got engaged in Paris last November and the actor is said to be "besotted" with the stunning 39-year-old South African.

May God bless and keep him — but far, far from me. - Madonna

"Sean is absolutely crazy about Charlize," an insider tells The Post. "He treats her son, Jackson, like his own, and the little boy already calls him 'Daddy.'"

The couple are even house-hunting in Los Angeles' picket-fence paradise, Pacific Palisades.

But the question remains: What does Theron — one of the most beautiful women in the world and an incredible talent (she won the Best Actress Oscar in 2004 for "Monster") who is, by all accounts, whip-smart — see in Penn and his reputation for violence, womanizing and hard-drinking?

Not to mention the fact that Penn, who once reportedly had a four-pack-a-day cigarette habit, hasn't exactly aged well.

You could wonder the same about Robin Wright, Madonna, Scarlett Johansson, Jewel, Petra Nemcova and Natalie Portman, all of whom have been linked to the actor, whose new thriller "The Gunman" opens Friday.

Madonna (married 1985-1989)Photo: Ramey

In 1987, Penn reportedly struck his then-wife, Madonna, across the head with a baseball bat. Madonna, mindful of the fact that her husband was facing a jail sentence for attacking a film extra, did not press charges — but the violence only escalated.

Robin Wright (married 1996-2010)Photo: WireImage

In December 1988, Penn allegedly tied Madonna to a chair in their Malibu home and attacked her. The nine-hour ordeal only ended when the singer was untied to use the bathroom and she fled to a police station.

Lieutenant Bill McSweeney recalled: "When Madonna staggered into the station, she was distraught, crying, with makeup smeared all over her face. I hardly recognized her…she had obviously been struck."

Penn was charged with inflicting "corporal injury and traumatic conditions" and battery on his wife, but Madonna later withdrew the complaints, and filed for divorce instead.

"May God bless and keep him — but far, far from me," she said.

Penn's second marriage, to Robin Wright, was also marred by volatility.

The couple called time on their 11-year union in 2007. In 2008, their divorce petition was withdrawn, then Wright filed for separation in 2009. Months later, they reunited, but the dissolution was finalized in 2010.

Scarlett Johansson (dated 2011)Photo: Splash News

"It was…difficult," Wright has said of her marriage. (She also subtly insulted Penn last week when she told Vanity Fair of her current love Ben Foster: "I've never laughed more, read more or come more than with Ben.")

Petra Nemcova (dated 2008 and 2012)Photo: Startraks

Despite his lengthy rap sheet — Penn's domestic misdeeds, assaults and scuffles with photographers have resulted in six arrests — the quarrelsome star has a "passion" (as evidenced in his dogged humanitarian efforts) and "magnetic charm" that his amours have all found irresistible, a friend says.

Good news for Theron: it seems the hell-raiser has changed his ways.

"He used to drink a lot, and that got him into trouble," the source reveals. "These days, he channels his aggression toward politics and trying to institute change. Being involved with Haiti really humbled him, and he's even managed to cultivate a friendship with Madonna."

Theron convinced Penn to give up his 65-strong cache of weapons — the guns were turned into a sculpture by Jeff Koons and auctioned off for Haiti relief. Penn admitted to Jimmy Kimmel this week that the couple does argue… "about whether or not we should fast [forward]" during "The Bachelor."

Theron insists that Penn "makes my life better," and the feeling is clearly mutual. He recently claimed that he had "never felt loved" in a relationship before meeting Theron.

"It could seem too late," said Penn, 54. "But to run into somebody now who you care about is a much more passionate, deeper, truer and — God! — a much happier feeling."