My husband is bisexual!

I have been with him since 2009. We are not married I’ve known about this all along we keep nothing from each other. He told me he would like to hook up with guys. I told him that would be his choice but if he is hooking up with guys, I am hooking up with guys too. He told me that I can’t hook up with the opposite sex only females. Does this sound right ladies? I am all for having a open relationship but I am not gonna be told I only can have sex with females!