Boyfriend gave me his Facebook password?

[MCJ]

There's no need to share FB passwords, there really isn't. It's not as much about trust as it is about having your own friends and having your own personal identity and human privacy. An example of the type of problems that can arise is, if someone sends you a message telling you something that THEY want private, but if your partner sees it first, they might say something to someone else and voila, you've got a bunch of drama on your hands. And that's just one example of the problems that can surface when sharing an account with your partner.

I'd just say thank you for trusting me with your account, but I don't want to go on your FB because I DO trust you and I respect your privacy. Hopefully he will understand where you're coming from and that'll be it...