What you say here (if I understand it correctly - I'm cautious!) follows the rules of sharing. But if you take cucking as a fetish, this in itself is supposed to be pleasure for him. He derives pleasure out of being denied pleasure. I find this difference to be in the background of a lot of discussions and misunderstandings here, so also here with the cage.
(and all this isn't even my personal fetish, I just see that a lot of people who are concerned about equality in pleasure see it the way you do and this is not the way I and many others understand the fetish. Cucking isn't sharing)
It is a delicate balance between soft and hard NTR. It usually begets many a heated discussions. I think as long as the story and characters are consistent with their behavior, desires, it can go either way.
I do not think cuckolding is sharing. The husband or wife becomes a voyeur and derives pleasure from watching, from being a witness, he/she is no longer a protagonist of the sexual action, merely secondary. You participate as an appendix
.
Sharing is equal I think. You participate in the intercourse with your partner, more or less than the invited person, but you are active.
But narratively it is weird, making an exaggerated example, when the wife goes from nun to nymph, from caring to dominatrix, in a few days, wanting to ride the whole town, while, abruptly, keeping the husband locked in a chastity cage.
