I have been in a couple of poly relationships. My wife of 15 years would probably fit into the category of the ethical slut. When I first new her, she was very promiscuous. She felt obliged to tell anybody whe had sex with about anybody else that she was having sex with concurrently. That included me.
Being rather English, I find that it is just good manners to ask me if it is OK to have sex with someone else. First I think it is a matter of politeness and just plain good manners to ask. Second ther might be a reson why I am uncomfortable with the poly male and might wish to say no. And third I find that simply being informed gives me the feeling that I have no say in the matter. I am of the feeling that it is not sufficient that I am in a ply relationship and therefore she should not have to ask on the basis that I expect it. And fourth I suppose, I find it erotic to be able to say yes and possibly to hear all about it later, or even join in. That is far removed from just being told about it with no say. Being asked is much sexier and more erotic in my experience. Am I worng?