full size Alex Pettyfer and Dianna Agron Attend the "I Am Number Four" Signing at Hot Topic on January 29, 2011
Credit: Araya Diaz/Getty Images for Dreamworks

Looks like things between Dianna Agron (Quinn), 24, and Alex Pettyfer, 20, have hit overdrive. The adorable couple are reportedly engaged!

A source tells People, “They're very happy about it.”

Dianna showed up for a press junket for I Am Number Four wearing a thin diamond band on her left ring finger, but said that her love life is "something I never like speaking [about].” Still, she did offer that working with Alex on the film was “great [...] because he was so enthusiastic and so determined to give everything he had to this character. He wasn't a diva, so that was good."

Source: People