Cameron Diaz worked with a lot of teenagers for her new film My Sister’s Keeper. So when we caught up with the actress at the premiere last night, we wondered if she liked hanging out with her younger cast. “We all just had a very natural synergy. We didn’t play house,” she told us. “It was very organic, and I don’t need to be these girls’ mother. They have a mother.” View our Party Lines slideshow for more fictional-family bonding.