I wouldn't worry about it. In my experience, the more you role play the less enticing it can be over time. Or, maybe he just has a slight fetish-type thing going on (not quite a fetish because he doesn't need it to get off).

I wouldn't worry too much unless it becomes necessary to role play for sex all the time. Even then I wouldn't worry if you're into it. If you aren't then you need to talk to him. Maybe tell him your fantasies. He may surprise you and find your fantasy to be even more erotic than his.

New things spark new reactions. Until it becomes an issue for you, there's nothing to worry about.