Sacrifice is something that has to be a decision made by the party making the sacrifice... If not it's just coercion, manipulation, or abuse. It sounds like you made your choices freely... You owe it to the good relationship that you have to be 100% honest. You do not want children. And if he wants children it will not be with you. So then he has a choice to make. And you shouldn't do anything to influence that choice further. If he genuinely feels like being a father is something his life won't feel complete without. Then he needs to leave you. And you need to let him. If it's a sacrifice he is willing to make and one that he won't hold against you as you continue to grow, then you can feel more secure in the decision to be together, knowing that he won't be asking that part of you to change. But he doesn't owe you the sacrifice of giving up something he's dreamed of. No one knows that to anyone else.