It is your shop, but its not illegal for the son to ask about it, its your choice to either talk to him about them or not, your choice as well to sell to the parent or not, personally as long as there is no nicotine in the ejuice, i see no problem with kids vaping as long as they are not stupid about it. but i dont vape and shit, i sorta am on the fence about buying one or saving my money, but i think you should of sold it to the parent because that brings in money to pay the bills,w.e. it's not your responsibility for her actions, it'd be considered illegal for her to give it to her child but at the end of the day you sold it to the parent, she was above 19. and I'd rather a child vape then smoke ciggs (14+)