He’s 48, divorced for five years now, with two teenagers, and you’re his 21 year old girlfriend of two years. The lucky thing is that he’s being straightforward with you. And it’s great that you’re so clear on what you want! That said, you have to consider that he’s focused on not remarrying and not having any more children. I get that this is disappointing for you, but while some people do sacrifice for love, others don’t. It’s important not to judge and instead to find compatibility. If you want marriage and children, it’s important that you date someone who wants the same. And if marriage and children are more important than anything, then those are your deal breakers. But if you prefer to be with him, while giving up marriage and children, then you can do that. It’s really your choice, and you’re not trapped.
I hope that helps!