Yeah you keep equating me to other people and saying I believe things I don't to try and "win" this argument. You are arguing with yourself.
Anyways, cheating is lying. I don't think sex is sacred. I DO think TRUST is sacred. I want my partner to trust me, so we have an agreed set of expectations and we hold each other to those expectations. Radical, I know.
Just because you don't believe in monogamy doesn't mean other people don't obviously. A relationship is an agreement for an expectation of behaviors. That can be different for different people, like poly people.
You have a funny way of selectively applying morality. Seems like you just dont agree with anyone holding you to any expectations. Good luck with that.