It was interesting, because during the first season, Sara definitely didn't trust him. And I think into the second season as well (which we saw in Ellie). That's understandable since she was brought in to investigate what happened to Holly, she made her recommendation and Grissom ignored it, and she probably felt upset about that. That being said, I think as the seasons went by they got more used to each other and the way they worked, and I feel that they were closer. As for a relationship, I really don't know. The only one I could ever see Sara with was Nick, but that's just me. Nowadays, I prefer him with Mandy One ship I never did understand (apart from GSR), and not that I am slamming anyone here, but it was Greg/Catherine. Seriously, what? She'd eat him for breakfast.