My (27F) boyfriend (32M) only wants to have sex when we are dressed as hobbits from lord of the rings

My boyfriend is a lord if the rings superfan and loves to cosplay. Personally, I prefer the hobbit trilogy but this is not relevant. I love my boyfriend and enjoy hanging out with him and we get along great. We have been dating for 21 days, but have known each other for a few years now.

The main cause for me to post here began when we became sexually active. When we have sex, my boyfriend loves to participate in foreplay. Recently this foreplay has revolved around the Lord of the Rings hobbits. He plays the part of Frodo and I play the part of Samwise.

This was fun for us at first, as I hadn't had sex in cosplay before. However, it got boring for me fairly quickly. My boyfriend insists that this is the ultimate way to have sex, as it aligns with both of our interests. I tolerated this for a while as it didn't seem to affect the sex itself, only the foreplay.

However, this would change. My boyfriend insists on me calling him Frodo when we do the deed. He keeps calling me his "precious little gardener", even beyond the bedroom. He also now says he "wants to drop the ring into mordor" when he wants to have sex. He will not use anything else to refer to sex

I have objected to things before, such as when he wanted to listen to the Lord of the Rings soundtrack whilst we have sex as well as not wanting to listen to this one indie band he likes. He has respected my objections in these circumstances and hasn't done it since.

I need some advice here to ask him if we could stop the hobbit sex or come to some sort of compromise. I'm not sure what to say and I still want to date him as he is very nice. However, I worry this may be taking things a bit too far.