Rachel Bilson believes it is ''natural'' for actors to date their co-stars.

The 'Waiting For Forever' star met her boyfriend of five years Hayden Christensen on the set of 2007 movie 'Jumper', and she thinks it's a normal occurrence to embark on a relationship with someone who you meet through work.

She said: ''Dating co-stars is natural. When you're working with someone, it's habit. I met my man at work. I'm attracted to mysterious men. Every woman can relate to that, right?''

But Rachel - who also dated her 'O.C.' co-star Adam Brody for three years before they split in 2006 - admits she doesn't play by the rules when she is in a relationship because she prefers to rely on her instincts when judging whether a man is right for her or not.

She added: ''I've been in relationships where we've said, 'I love you' after two weeks. I think it depends on the person and the relationship. If it feels right, go with it. Love shouldn't play by the rules. It's all about chemistry.''