Telling someone something he does not understand is pointless, even if you add that he will not be able to understand it. (That so often happens with someone you love.)

If you have a room which you do not want certain people to get into, put a lock on it for which they do not have the key. But there is no point in talking to them about it, unless of course you want them to admire the room from outside!

The honourable thing to do is to put a lock on the door which will be noticed only by those who can open it, not by the rest.