I think its a great idea to see if you could foster him. If your hubby doesn't want you to foster, maybe you can encourage the shelter to find him a foster home. Tell them the change in behavior you noted when you had him in the other room.

If neither of those ideas work, could you hang around the customers at the shelter and sort of let them know about the sweet boy. Maybe you can convince someone to take him.

And if THAT doesn't work, just threaten your husband