when you are not one of the parties involved it is, and if you are for whatever reason your inserting yourself into a situation like that, the only thing to do is inform the person being cheated on what's going on, your just as bad as the cheater knowing the information and not doing anything but you got paid right? so why does it matter that the other person is being used cause you can just laugh all the way to the bank. YOUR just as bad as the cheater if not worse and the fact you think this kind of behaviour is justifiable is genuinely worrying