'The OC' couple get engaged off-screen

Engaged: Bilson and Brody

Adam Brody and Rachel Bilson, who play Seth Cohen and Summer Roberts in American teen drama The OC, have announced their real life engagement.

Despite efforts to keep their relationship quiet, they are now officially engaged and seeking a home together in Los Angeles.

A source at Fox network said: "They are both so much in love and want to settle down together.

"Adam went down on bended knee in a very traditional way and they plan to get married in the new year. It's the talk of the set, but they have been trying to keep it quiet."