Oral and anal help!!!

I love giving my man head, but here lately, he says I've been using my teeth more and it hurts. I just got done trying to give him head and we had to stop because of the teeth thing. Any tips on positions that can eliminate this problem? We've also decided to try anal in a couple days. I've done it with someone else before, but it was very painful even though the guy was pretty small. My current bf is far from small. Any tips on this too? I know that alcohol will be a priority that night lol.