i need help

this is a bit personal but i really have nobody to talk to about this. i thought i'd feel better if it was anonymous online so here goes
my partner wants kids in the future. i dont.
we don't intend on breaking up over this cus we've been together since high school. we're in our early twenties and i am really sure that i dont want to start a family.

even the thought of marriage scares me. i think i will eventually want to marry my partner but i know i'll never be open to having kids.

(i'd prefer it if adults answered this instead of the general ten year old populace on mangago)