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.
I asked my wife’s parents first for their consent before I proposed to her, but that was a marriage proposal and we were both in college. I didn’t ask them if I could date her, but she wasn’t a high school kid.