Is the male chastity fetish selfish?
To me that’s potentially one of those hair-splitting gotchas like “if charity makes you happy then it’s not truly altruistic! (I am very clever)”
Having a service mentality or being affectionate because caged is still because you made a choice to be caged. Humans aren't wired for long term monogamous sexual happiness, everything we do to make relationships work is a hack. So the cage is no different from drinking wide together to relax or getting fit or her dressing in particular clothing to get a specific response from you. It's OK to make choices to manufacture particular moods.
I think when it comes to the male chastity fetish, the possible selfishness is less of an issue for sustainability than the category error men often fall into.
Women who are at least initially enthusiastic about male chastity but aren't already enthusiastic teases and playful dominants aren't going to magically become all singing and dancing keyholders.
Generally, such women like male chastity day-to-day for the same reason people have their dog "done". It's a sort of "neutering lite" with deep symbolic undertones and a domesticating effect. The self-curated sexual experience is a major bonus on top of it, but it's not why they like us locked outside the bedroom.
What happens is that male chastity fetishes get a "yes" from a wife or girlfriend and then put a lot of time and talking and pestering into “educating” her to be a “proper keyholder” when she's not really their keyholder in that sense. Once you've behaved that way, it's hard to row back, and maybe everything looks like a play to the woman.
Hence my Chaste Manifesto…