Would you go forward in building a life with someone who you know you may end up needing to let go?

I ask this because I don't want kids and never really have, and up until now I thought my boyfriend was on the same page. Tonight he confessed that he would like to have at least one kid in the future because he thinks that we would make a beautiful baby and that I would make an amazing mom. It's not completely surprising to me though because he's made accidental comments about being a father in the future and I think that, even if part of him thinks he'd be content without kids, a bigger part of him always has. I still don't want kids though and I never see myself wanting them, although I am open to the possibility of that changing. But what if it doesn't? It's far in the future but if there is this possibility right in front of us of needing to let each other go in the future so as to not take this away from or force it upon the other, then what would be the best way to go about this?