He lives with his mother and her parents.

I have a little experience with step kids, but I'm a little afraid of giving advise. I can tell you a few things that I learned.
You're fortunate that he lives with mom. It doesn't matter how much you love them, or how good you treat them, you're not mommy. Kids naturally want both parents together. In their eyes, step parents are outsiders who keep their parents apart. They very often will resent the step and misbehave to try to get them to leave. The two step children I had lived with us. They told me that they hated me. I finally left before I ended up in prison or a straight jacket. Literally. I had already had CPS called on me for spanking them. I was told by CPS not to spank them again. They tormented me 24/7.

If you can stop playing the middle man, do. You will be the one to get hurt. They will have to work things out themselves. Try and be neutral if you can.

Never say anything negative about the child's mom in front of him. Always try and be kind and positive. It may be difficult at times.

Let dad do as much discipline as possible without letting the child run over you. Especially if you believe in spanking. Let dad spank. You give time out or something if needed and dad is not home. No mother wants someone else spanking her child. Especially a new wife.

Try to be the child's friend, but never his mom. It may take time to earn his trust. Just be patient.

I hope this helps a little. I hope I haven't stepped on any toes. It's difficult trying to give advise when I don't know your whole situation. I tried to keep it pretty basic. I'm no expert. I can only tell you from what I have experienced in my 50+ years, and what I have seen my friends go thru.

Thanks I really appreciate the advice. I have never said a bad word about his mother in front of him. I have learned that from seeing friends with step children as well.

Your right there is a whole lot more to the story, I guess what bothers me the most is that the mother really isnt hurting me or my husband in the end she is hurting her son with the things she does or says to him. I will just have to take things one day at a time and just from there.

Thanks again for the advice.