Honestly the amount of people who spout this crap about his body his choice. Him taking responsibility etc. I don’t believe for a minute that any of you would be happy for your husband to go and get life changing surgery without even a discussion with you, and then for you to find out by accident.
It is incredibly deceitful and it has broken the OP’s trust in her husband.
This is not how healthy relationships work.
I would be both angry and incredibly hurt if my husband did this.
But then, my husband tells me if he is popping to the shop for bread, so I would expect him to tell me if he was going for surgery.
Sorry, but those who say it’s his choice are full of absolute shit. And so black and white. You don’t genuinely believe it either.
Of course he can do whatever he wants to his own body. But he has to expect that making life changing decisions without discussing them with his partner will have consequences.
If he is dishonest about this what else is he keeping from the OP?
OP you are 100% not being unreasonable.