Sulekha community - Advice from neighbors and local experts

I just have a question regarding long hair. I have an XX year old son that is constantly pressured by my father to cut his hair. I am 48years old. I have X kids. I am happily married to a Catholic girl for X8 years now. It is creating problem in my house now because my wife and her family are looking for answers. I know it's always been about cultural upbringings. We try to follow some of the practies like shaving his head when he was X(which was also a problem but we got through it) It's seems like my dad does not value everyones else's opinions. It's only his way. He is persuading my wifes family to get him to cut his hair. THey feel uncomfortable too. Can you answer this question? No one can. I will even make a donation but just looking for some unbiased guidance. Thank you for your time.