His behavior is what we call topping from the bottom.
He is being manipulative which is not a desirible "sub trait" it is even more so not a good poly trait.
I would put my foot down and state it as clearly as i can.
NO I am not mono..you choose to be.
NO I am not into BDSM...you are...your choosing to force it upon me.
you are not responsible for his happiness. He is. You are not reasonsible for his needs beng meet ( in realation to BDSM) he is. He is choosing to be mono which means this is his choice to deny his own needs. Don't allow yourself to give in or feel guilty.
If he can not respect you as a person then he has given you no other option, but to leave and divorce him.