Last Arguement

I don't get into too many arguments, because I'm a pretty chill guy, but the last argument I was in got a little heated. I was working my swing shift at the casino in Marquette as a security guard. While I was at the front door asking for ID's for anyone that looked under twenty one this younger guy and his family said he didn't have his ID on him. And as a rule of the casino I told him he wasn't aloud in, and they didn't take that answer to well. He repeatedly told me that he was eighteen and that I should let him in the casino, I told him no and again that he had to have his ID on him. Then his mother jumped in on the argument and asked if she could show me her ID to prove that he was eighteen which made absolutely no sense to me so I said no again anyways. The mother was mad with me and said that the whole situation was stupid and that she didn't like me. So since the kid was pretty cool with it, I stood outside with him while his parents went in to gamble.