Charlize Theron, Sean Penn ‘Not Engaged Yet,’ Her Movie ‘A Million Ways to Die in the West’ With Seth MacFarlane Red Band Trailer Released! [VIDEO]

Charlize Theron and Sean Penn are getting serious. According to People, friends of the Hollywood power couple “wouldn’t be surprised” by a proposal, but added, “She’s not engaged – yet.” The two took their romance public back in January at Penn's third annual Help Haiti Home gala.

The Oscar winners also spent Valentine's Day weekend together in Cabo San Lucas. "They were inseparable," an eyewitness told PEOPLE of their Mexican vacation. "They held hands everywhere they went." Late last month, Theron and Penn were spotted arriving at The Forum in Inglewood, CA for Chelsea Handler‘s stand-up show. The famous pair was spotted holding hands and walking outside of their Greenwich Hotel in New York City earlier this week.

Penn, 53, is also planning to direct his girlfriend Theron, 38, in ‘The Last Face’ also starring Javier Bardem.

Penn was previously married to House of Cards actress Robin Wright. Penn and Wright married on April 27, 1996 and were divorced on July 22, 2010. Theron was previously dating Irish actor Stuart Townsend for almost nine years before separating in January 2010.

Meanwhile, Theron’s next movie, "A Million Ways to Die in the West," a raunchy western comedy, which was produced and directed by Seth MacFarlane (Family Guy, Ted) just released a red-band trailer, which can be watched below! The film also stars MacFarlane, Amanda Seyfried, Neil Patrick Harris, and Sarah Silverman.

According to the film's official synopsis: "After Albert backs out of a gunfight, his fickle girlfriend leaves him for another man. When a mysterious and beautiful woman rides into town, she helps him find his courage and they begin to fall in love. But when her husband, a notorious outlaw, arrives seeking revenge, the farmer must put his newfound courage to the test."
"A Million Ways to Die in the West" premieres in theaters on May 30.