I think you're fine. I also think it's great that you are able to admit that you love sex. It seems that so many people, women especially, feel that sex is something you shouldn't talk about, much less say you want to have more of. Sex is a beautiful and powerful part of life when used right. But, if it's used against someone, as in a rape or incest case, then it is a horrible and terribly destructive weapon probably more damaging than any bullet known to man (because it damages the mind).
Usually, when people of "nice company" think about using such dark and demanding language in conjunction with sex, they are more than likely thinking of a rape. But this is not necessarily the case. As long as everyone involved are consenting people of legal age, then it is part of the beautiful sexual experience. Some like it hard, some like it soft... just like food, music, movies, and clothes, we all have different tastes in sex. The key is knowing what you like and finding a partner who likes it the same way.
Try to convince your boyfriend that as long as his roughness and language is within the context of rough sex, it is OK. But if he were to treat you that way when not in that role playing mode, that is when it becomes wrong and demeaning.
I hope this helps!