Ugh....how many times have I called out someone on their hypocrisy and got the "I know but I can't help how I feel!" spiel.
That statement always comes from a selfish person, in my opinion.
Sorry but what's good for the goose is good for the gander. Either both get to have outside relations to their hearts' content---or nobody does. End of story.
If the rules & boundaries ain't equal, it ain't polyamory. It's subjugation.