Did you ever stop to think maybe she views your diaper's as "The Other Woman" competition for your love, because she feels like when you wear your diaper there is no chance in hell of anything romantically spontaneously happening because she is not going to take your diaper off to make love to you or to start a little foreplay leading wear ever it may??
maybe you need to have a "Date Night" in your marriage thats a special night of the week that is "Fetish Free" no kids around type of thing and you more or less just get into each other and do whatever you want for the whole night,Maybe surprise her treat her like a queen one night and worship her make a romantic dinner run a bath for her, watch her favorite movie together, and see where that leads maybe she will then surprze you on a night , maybe even with a fresh diaper.
Let her know she is not in competition with the diaper,You Love Her, whereas the Diaper makes you feel Secure and safe like when you where a kid (i'm not in your head this is just an example but tell her what the feelings associated with the diaper are , diapers are plastic and absorbent material that you throw away when done with you sure as hell did not exchange wedding Vows with it and you don't love something that does not even have a pulse, you may like it but it's not love.these are of course suggestions on how to make your marriage better and stronger and also may help Integrate your diaper needs with your marital and family obligations.
Nappy