Is it normal to want a ffm threeway with my fwb

We are just friends with benefits I guess you can call it that. He says he will never have sex with me again because we are just friends but we also do sexually stuff usually starts off with innocent kissing and flirting. We are also stoner/drinking buddies who hang out once in a blue moon. For the last 9 months ever since I told him. I am into girls too. He wants to have sex with me and another girl. I was wondering if it is normal for fwb to do this also. I usually hear about people in committed relationships doing this.