I don't understand why you can't tell him to stop it and respect your wishes. If you've been together a long time, you should be able to say to him what you posted here. Why do you stay with someone so disrespectful and inconsiderate, and with whom you cannot communicate, anyway?
If he wants to be poly and have relationships with other women, that doesn't mean you have to be involved with them. You're straight, right? He can go fuck them on his own, if you're into being open. What he's been doing is just plain idiotic and sounds like he is clueless. It is so ridiculous that it almost has me wondering if this is a real post or not. If it is then... DTMFA!