Must be in Quick play.
As a kid, win a match by escaping and not having seen the neighbor once.
I did this after 20-30 times doing it successfully with the achievement not popping. Finally it did pop with one difference, assuming it isn't bugged of course. I was the last person through the door. In my prior attempts I was usually the first if not right behind the first kid through the door. This would cause me to have to spectate the other players, including the neighbor. I think for some reason the game was counting this as me seeing the neighbor. Hope this helps, if anyone else can confirm my theory is correct it would be great,