My Boyfriend and I have been together for a long time, and I care a great deal about him. With that said, my boyfriend doesn't take good care of his teeth at all. We live together, so I see that at night he doesn't brush his teeth. This happens every night. Now that we have been together for many, many years, I bring it up to him. He gets really upset when I mention it. I don't want to become a nag, so I leave it alone, but then he also gets mad when I don't enjoy kissing him due to his breath. What can I do to send the message that he needs to take better care of his teeth more directly? What can I do or say if my boyfriend is upset when I bring it up?