"They're dating again," a friend of the actress tells PEOPLE.
And they're not hiding, either.
Last week, Christensen was seen leaving Bilson's house in Los Feliz, Calif. With Bilson based in Los Angeles and Christensen living in Canada, distance was reportedly one of the main reasons for the split.
Christensen, 29, and Bilson, 29, met on the set of Jumper in 2007, and got engaged in December 2008.
Reporting by ALEXIS CHIU