Actors Sean Penn and Charlize Theron attend the French fashion house Christian Dior Haute Couture Fall/Winter 2014-2015 fashion show by Belgian designer Raf Simons in Paris
(L-R) Actors Sean Penn and Charlize Theron attend the French fashion house Christian Dior Haute Couture Fall/Winter 2014-2015 fashion show by Belgian designer Raf Simons in Paris July 7, 2014. REUTERS

Odd couple Charlize Theron and Sean Penn shocked the world when they started dating and were spotted for the first time during a Hawaiian getaway in December. After dating for 8 months, the Oscar winning couple is planning to wed in Theron's native home in South Africa while filming their upcoming movie "The Last Face," where Penn is directing while the 38-year-old actress is starring the film.

Before taking their relationship to the next level, the power couple are known to have been friends for 18 years. Sealing the deal seemed to be the best option for both of them. Skipping the formal engagement announcement, the two stars decided a semi-secret wedding while shooting their movie, according to the latest July edition of Us Weekly.

The duo have a lot of agenda while visiting South Africa this summer as they also intend to adopt a child after tying the knot. "They want to get married very soon," a source told Us Weekly. Based on Penn's confidant, the Hollywood actress "always intended to have another child" after she became a mom when she adopted her now 2-year-old son, Jackson.

"Charlize Theron and Sean Penn are mixing business with pleasure," according to a source. "While in Theron's native South Africa this summer to film The Last Face (Penn is directing; Theron plays a relief worker), the couple plan to wed and adopt. Eighteen years of friendship and eight months of dating has proven to Theron, 38, that Penn is a father figure."

The marriage will be the first for Theron who split for her longtime partner Stuart Townsend in 2010, and the third marriage for the 53-year-old actor. Penn's first marriage is with Madonna in the late 1980's, followed by Robin Wright where he fathered Dylan, 23, and Hopper, 20.

Known for his volatile romantic history, nobody expected that the "Mystic River"star will be sticking with the actress and even plans to marry her. "But somehow, the relationship gods decided to put Charlize and Sean together to prove that no matter how incompatible a couple may look, they can always find common ground - even in Hollyweird," Celebdirty Laundry reports.

But unfortunately not everyone is happy with their upcoming union, Sean's daughter Dylan Penn is getting in the way of her father's happiness. The topless model allegedly hates her mother's replacement and there are reports that things turned ugly during a recent dinner party between her and her soon-to-be-stepmother.

Representatives from both stars have yet to speak up about the alleged union.