will not work til you two are on the same page. I feel sorry for all of you- get help /nanny 911
I believe in parents that work together will always come out on top. When you and your partner can't agree on how to controll your 9 yr old only confusses the child. I am 26 yrs old and my husband is 44 I have several step children ranging in ages from 25yrs - 10yrs old. From one step parent to another try sitting down with your step-son and in a clam voice and with an open mind and see if he will open up to you and tell you why he is so angery and why he has issues with you and see if you and your partner can agree on a solution of punishment. I hope things get better for you.
P.S If partner is talking down to you let him know how you feel he might not know he is doing it.
Step children can cause many problems in relationship unless you work together and compromise on the parenting. My DH has two children from his first marriage that live with us but they are much younger(1 and 3) so it was easier for the kids to adjust. If you are raising them with him, you both need to sit down make the rules of your house and then sit the kids down and go over them. Tell them what the punishments for bad behavior and rewards for good behavior will be. Then you and your husband have to stick to it. Consistancy is the best policy. To help things, treating them like your own instead of step children could help as well. I hope this helps. Best of luck to you.