Their parents trust me to talk to their kids about things they didn't feel comfortable about. Their parents ask me to look out for their kids and implicitly understand that I'm told things that they aren't. I think it's a cultural difference in the role of education between Asian cultures and others. I was even occasionally asked by parents to take a bigger role than I was sometimes comfortable with, for certain things. I was not undermining the parent's roles. I understand your reservations, but they're misguided at best. The parents were who encouraged their kids to call me big brother and have shared their appreciation to me privately.