Fiancé isnt sexual nor into sex?!

So ive known my fiancé for some time now and we are both virgins. Im definitely more sexual between the two of us but I get nothing in return from him? No dirty talking? No planning our sexual endeavours after marriage? Anytime I bring up something sexual he changes the topic. I thought maybe it was because he was shy or a "good guy" and at one point i was worried he may be gay aswell :/ i dont know what to do? Im scared to bring the topic up with him. We have amazing banter and get along really well but im super sexual (even though ive never had sex) and i love talking about sex or dirty talking and get nothing back from him.

Has anyone experienced this with their partners?