If someone is “young” and “immature” he or she has no business getting married. It’s not fair to the person. It’s not fair to the spouse. It is completely irresponsible to do to their children.
If someone is mature enough to enter do responsibly marry, enter into contracts, go to war, die in childbirth, own repeating firearms, run a business and make medical decisions it is past time for the parents to give advice and not make an issue out of it when the adult son or daughter makes an adult decision.