I'll start by saying my dad has never pressured me to have kids, but I do think for a long time he thought it was a phase i'd grow out of it. Especially since my brother was on the childfree train until he wasn't 😉
A couple of weeks ago my dad and I were babysitting my 6 year old niece, and after she went to bed we were sitting on the couch and he turned to me and said "aren't you glad you don't have your own?!" - not necessarily in a bad way, my niece is a gorgeous, fun kid and I love her to bits, but I think he's more understanding of how hard having kids is AND that my energy and personality would just not be suited to having kids at all.
It was such a nice feeling and honestly I was kind of surprised how much that recognition meant to me, it was so affirming in such an unexpected way.