I would encourage him to read this thread. I think that both your sentiments laid out so fully and clearly, and the advice given so far, are just what he needs to see in plain language. If that's not enough to make him realize that the way he's acting is driving you away and accomplishing the opposite of his goals, then I don't know what will.
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.