Life & Style has learned that after only four months of dating, Sean Penn is ready to marry Charlize Theron.

“Sean’s fallen hopelessly in love with Charlize,” a pal close to the couple, tells Life & Style, on newsstands now. “He’s telling friends that he wants to marry Charlize by year’s end!”

But it’s not just Charlize, 38, who Sean has grown close to. Her son, Jackson, 2, have also found a permanent place in his heart. “She opened up his sweet, romantic side,” says the pal, adding that the Milk actor, 53, already has forged “a father-son bond” with Jackson.

And Sean, who has two older kids from his marriage to Robin Wright, has even begun turning his Malibu mansion into a family home, building a fence around the pool and buying a trampoline with a safety net. “He’s a completely new man,” says the source. “He’s truly in love.”

Source:  LIFE & STYLE WEEKLY