Is this normal?

Okay so my boyfriend just randomly got into the whole eating ass thing. Well last night we were drunk and I was giving him head and such and it turned into him asking me to eat his ass. I did it just because it's something he wanted and if he likes it I'll do it. I've never had a guy like that before so I'm just curious. He was molested as a child so could it be like a comfort thing, or are there guys out there who actually enjoy it just to enjoy it.