I've finally decided that I'm not going to tell my now ex-girlfriend that I had a vasectomy long before we met
That is probably something you should tell them. Would you tell them if you were in my shoes?
Why are you even asking me this question?
Haha sorry, just trying to lighten the mood. But anyways, why do you have to lie to your ex like that? It was a very important decision and she may have wanted children, but it doesn't matter anymore since she is an ex.
I was going to tell her the truth but then I saw that she had a lot of debt and I felt like my decision would make it a lot worse.
What's in the past is in the past now, she is your ex and you don't have to tell her anything anymore. But for future relationships, wouldn't you think it's good to come clean right away and not lie? What if they really want kids, and you only told them when you were engaged?