You choose to wear diapers. You made an informed decision to do so. You child cannot make that decision. Whether or not he wants to wear diapers, he has a right to be toilet trained and later, when he has the power of reason, he can decide whether he wants to wear diapers. If your child is resistant, that's to be expected. Toilet training is dificult, wearing diapers is work-free. That's not a decision that they enjoy diapers; it's a decision to not do any work.
Being a parent means, among many other things, making decisions for your child. You're the parent, and you know what is best. You wearing and he wearing are not the same thing. Once your child has control of their bodily functions, and IF they decide they want to wear diapers once they are older, which is extremely unlikely, even then you get to decide if they can do so and under what conditions. If right now you decide to leave him in diapers because you feel hypocritical, then you are making a decision that is unfair to him and that will have negative consequences for your child for a long time to come, in effect forcing your sexual fetish on your child, and you will have done all that for selfish reasons. I don't think you are that kind of person.