Fuck those parents. I hope he grows up to be someone either rich or powerful and when his parents can try to beg him for money or favors, he can show them this video before pissing all over them and sicking dogs on them.
I have a very close family member comes out as Gay within the last 5 years. When he told me my only response was that my love for him is constant and I will support him in any way he wants and if he wants me to march in a Gay Pride Parade and support him I will and not care what anyone thinks because I only care about him and standing up and supporting him.
The family was way out of line for hitting him. Both sides were emotional and insulting each other, but that's no reason for violence. I believe it was real. It could be he has been smacked around before this.