Another point to the finding a girlfriend first idea:
If it's going to be a serious relationship, you gotta be honest, and if you share something like infantism, she owes you a pretty big secret about herself! 😉
Also, if she's not into it, well, there's prolly a lot of other women who will. I think, if ya'll are like me, we're just lazy: we'd rather know she's cool with it from the git-go, so we don't have to worry about either rejection, or the work it'll take to get her into the whole idea. Well, I guess I aughtta stop being lazy, or I'm going to end up in a deep rut.
As to the question: "Whats the best way to find a girlfriend that wont have a problem with diaper" -- I went to a speaking engagement hosted by Daddy Russ (from what was, at the time, SIDNY), and he said what works for him is to pick up women at a known kink bar ( NY's got a ton, so he's kinda lucky in his location), because you know they're at least open minded.
Just some thoughts,
Nolv