Ethical behavior are just rules that guide effective operations of every relationships. It does not define the real concept.

That you have been practising poly for long doesn’t mean you have being doing it right. The fact that your think having an affair outside the existing partnership is cheating clearly means you do not understand what “open relationship” means and that is why most people in open relationships struggle with accepting the reality.

Please poly and other form of open relationship means the partners are entitled to sleep with anyone they choose to. Being honest and communicating who you have sex with aside from your partner doesn’t change the concept that they are free to do as they please.

And when you think about it, you will realise that honesty is also a reason the other partner easily gets jealous. I practice an open relationships and I don’t expect my partners to discuss their sexual encounter for the same reason most polys regret (emotional distress).

I agree poly partners can be disloyal but that does not apply to having sex with other people. Have a nice day!