Were you 30?
No, but it seems customary to get the approval of the parents in any relationship. I’m not defending him by any means, a 30 year old and an 18 year old is really weird, but I don’t get why asking the parents for approval is weird.
It does seem like an old fashioned thing to do if the woman is an adult. (If she isn’t, and you are, you shouldn’t be dating her unless you also aren’t an adult)