took us 8years, but we did meet at 18 and tbh we couldnt afford a place, so i lived at my parents and his mum moved away when he was 19, so he rented a tiny bedsit and i stayed there at weekends much to my mothers disgust!!!
we were going to buy after a few years, but my parents told me to stay with them for 3years, i paid £60 a month to them and put rest away in high savings account and then we had a big deposit
brought a house when we were 26
as you get older, you tend to move in quicker, but I think the OP bloke wants his cake and eating it as well
why would he want to move out from his parents, where he prob pays min rent, and maybe gets washing done, doesnt have to clean etc
to move out, pay rent/mortgage is scarey, let alone tsking on 2 small children as well
but if you are not happy fruitcake then you need to have a chat with him - see where the land lies, does he see himself moving in/where is your relationship going etc