Charlize Theron and Sean Penn rang in the New Year together in a vacation for two in Hawaii. Charlize didn't bring her son. Rumors have been exploding all over the net that the two Academy Award winners are dating. Theron reportedly stayed at Penn's beachfront home in Oahu, spent New Year's even with Penn, took the same flight back to Los Angeles and were photographed leaving Theron's house in separate cars.

Speculation that Charlize Theron and Sean Penn are dating exploded after People magazine reported that the two were seen vacationing together in Hawaii and E! Online said Charlize and Sean stayed together after their return trip to California. Penn's ex-wife Robin Wright recently got engaged to Ben Foster. Theron is the mother to 2-year-old son Jackson, who was not on the vacation.

Charlize Theron, 38, and Sean Penn, 53, are longtime close friends, but when they were photographed vacationing together at Penn's home in Hawaii the romance rumors went into full swing. This isn't the first time Penn and Theron have been linked romantically by the press. Sean and Charlize were seen having dinner together in 2010 and set off a flutter of gossip activity.

E! News cited an eyewitness who said Charlize Theron and Sean Penn didn't end their time together when they left Hawaii. They spent more time together when they got back to California. Penn and Theron were seen leaving Charlize's home in Hollywood Hills, Calif., at about  9:45 a.m. on Tuesday, Jan. 2. Charlize pulled out of her security gates in her Lexus. Sean Penn exited the gates in his truck.

Sean Penn was married to Madonna and Robin Wright and has been romantically linked with  Scarlett Johansson. Charlize Theron keeps of her love life private. The "Monster" actress split from nine-year boyfriend Irish actor Stuart Townsend in 2010.

Penn and Theron were on the celebrity guest list at "Family Guy" creator Seth MacFarlane's holiday party in December. They threw MacFarlane a party for his 40th birthday in past October.

A source says "Charlize and Sean have been friends for years. They have been spotted out together several times in the past few years. Even when Charlize was dating Stuart [Townsend]. They both had dinner with Sean several times."

Sean Penn can currently be seen in "The Secret Life of Walter Mitty." Charlize Theron will next star in Seth MacFarlane's western, "A Million Ways to Die in the West."