The OP attempted to find a middle ground by suggesting they might agree to have children later, but then explained that forcing herself into parenthood if unprepared would be unfair. This led to the boyfriend abruptly stating he would leave her for someone else if she did not commit to having children. Feeling unsupported and hurt, especially after showing empathy for his potential future feelings, the OP ended the relationship. The central question is whether the OP was justified in breaking up with her boyfriend over this ultimatum.

I 21(F) have been dating my 22(M) boyfriend for 4 years now. We recently started talking about our future together and the kids issue came up. He has known for a long time now that I’ve always been iffy about kids.
He, on the other hand, insists that he likes kids, and would like to have them in the future. This issue has often caused a massive strain on our relationship, but we’ve chosen to cross that bridge when we get there.
So, this past Saturday, the issue cropped up and the conversation turned into a sore argument. My boyfriend said that living without kids would make his life pointless, and he feels like he would resent me in the future if I made him do that.
I listened to his argument, and it made sense. After all, we’re both young, and have some more time before we get there. So, naturally I’d assume that maybe I’d change my mind in the future, and we’d be able to have those kids.
I shared these sentiments with him to which, I got a positive response. But here’s where things got heated. After I told my boyfriend that it would also be kind of unfair to force myself into having kids if I’m not prepared, he suddenly changed the tone and said he would have no choice but to dump me for someone that would give him kids.
This came as a surprise because I had assumed that he only wanted kids with me, and would also try and view things from my perspective. I felt so bad, because I expected the same support I had shown him when he told me he would resent me for not having them.
I explained my disappointment to which he said that he was equally disappointed at me for being selfish. I got mad, and broke up with him then. We haven’t talked since then.
Conclusion
The OP finds herself in a difficult position, having ended a long-term relationship because her partner introduced an ultimatum regarding a fundamental life decision—parenthood. The conflict arose because the OP felt her boyfriend was unwilling to offer the same emotional support and consideration regarding her reservations about having children that she had offered regarding his desire for them.
The reader must now consider the responsibility each partner held in this relationship: was the OP wrong to prioritize her comfort over his stated long-term desire, or was the boyfriend’s ultimatum and refusal to validate her feelings an unfair way to handle a deeply personal divergence of life goals? The core debate centers on whether a fundamental incompatibility like the desire for children warrants an immediate breakup when one party issues an ultimatum.
Here’s how people reacted:
If he wants kids and you don’t, it’s not going to work out. Ever. Either he resents you for not giving him children or you bow to pressure and resent having had kids you never wanted.
I know you’re very young and having kids is probably a decade off in the future even if you did want them, but it’s not worth staying with someone you fundamentally don’t want the same future as.
You’re not selfish in the least for not wanting kids – and the fact that he threw that at you is a red flag about what kind of guy he is.
Best to move on.
you are fundementally incompatable, and it’s a good thing you’re finding this out while you’re both still young.
he wants kids. you might not. your life goals are different. there is no point in wasting each others time any longer.
Can’t blame him. He feels his life calling is to be a father. You two are probably better off apart.
You all need to end things.
NTA.