of birth control completely failed us. You can't get a more permanent non-permanent birth control than an IUD, and the IUD up and disappeared. And not because the wife and I weren't on the same page either. I was actually ecstatic, she was PISSED. Thankfully that wore off (for her, not for me), and she's the joy of our life.
But, we were getting older, there were medical concerns for my wife "risking" going through the process again, and we both independently got the strong impression that what happened to get our last one here needed to happen to get her here, and that our family was now whole.
Plus, if it's either the man or the woman to do the deed, it's pretty dang selfish of the dude to expect her to do it. For a woman it's very invasive, and a lot riskier, than for a man. Mine was a 15 minute procedure and a long weekend taking it easy, and that's it (okay, okay, providing a verification-of-effectiveness sample a few weeks later was awkward as yewt, but whatever).
Easiest choice ever.