I gotta ask… On the third kid thing… You do know the concept of birth control, right? And that there are forms of BC for men as well as women. Surgical or condoms… you could have prevented #3 if you didn’t want #3.
Hypothetically, if your wife told you she was practicing birth control, but wasn’t, then you’ve got bigger issues. From what you’ve written, you guys have been married a long time and seem to be on the same page except on house buying… I’d like to think your wife didn’t intentionally trick you.
If you knew the sex wasn’t protected – then yes, YOU made a choice to have a kid… or at least made a choice to open up that possibility.