Bad Boy Tamed? Sean Penn Quits Cigarettes For 'Thrilled' Fiancée Charlize Theron

Sean Penn thinks his fiancée Charlize Theron is so smoking hot, RadarOnline.com has learned that he gave up a longstanding cigarette habit as they prepare to walk down the aisle — and the Academy Award winning actress didn't even have to ask!

"Sean had been a very heavy smoker for years,” an insider told RadarOnline.com. "After dating Charlize for just a few months, he decided to give it up. Charlize hadn't pressed the issue, but just asked him to abstain whenever he was around her son, Jackson. One day, Sean just announced he wasn't going to be smoking anymore."

"Charlize was happily stunned and was thrilled Sean was quitting,” the source said. "For the first few weeks, Sean used a nicotine patch, and would occasionally use the gum version.”

"Sean told Charlize he was quitting because he wanted to be the healthiest version of himself for their little family,” the source continued. "He is absolutely head over heels in love with Charlize."

As RadarOnline.com reported, Penn is in the process of adopting Theron's adorable son.

The A-list couple became engaged in November, and Penn “has already begun the paperwork to formally adopt Jackson,” an insider previously told RadarOnline.com. “Charlize never placed any pressure on Sean to adopt Jackson. It has been a very natural process of them becoming a true family.”

“Jackson calls Sean 'daddy,' and Sean just lights up around him,” the source continued. “Sean picks Jackson up from nursery school, and all of the parents know him.”