Hello! I feel your pain :)
First of all if it is respect you want with your child, you are not on the right path. Being respectful also means to choose your words kindly. Smarting off and talking back is not respectful and trust me, he is only 8. it is only going to get worse when he gets older. I know, because I have a 10 year old (going on 30).
I had to change my parenting strategy with my son a bit. The simple stuff does not work with the big kids. He is just too smart. I have 3 more that are younger and time out works great until they are 7 or so.
It is so important that he learns that he is not the "little king" in the house. To lead a successful and happy life one must be able to adapt to rules and respect other people and their space. One MUST be able to yield to others and be ok with it. I assume since he is your only child you have catered to him until now. It did not matter to you, he is the only one that had a need and you molded your life around him because you love him and you wanted him to be happy....the weird thing is that kids don't get that. Instead of appreciating what you do and loving you even more, they learn that their need is to be met always and start to expect to be treated this way everywhere. It frustrates them to no end if you change your tune and something does not go the way they are used to. It makes them very angry. Coping with "no" or "not right now" must be learned.
SO
it is high time to set a few boundries. You are lucky, he is only 8!!
First of all, you ( -and your partner) are the parent(s )and you call the shots.
This is not a friendship, this is a parent/child relationship.
Second, talking back, making rude comments, walking out or smarting off - is rude and not acceptable.
Thirdly, hitting, destroying stuff hurting the other kids or animals is also not acceptable.
And your work needs to be done in a careful matter ( homework, music lessons house chores etc)
Talk these things over with your child so he understands what is expected from him. Tell him that bad behavior has consequences. Every time he steps out of line you will make a note, every day he is complying to the rules he gets a star ( -on a chart or wherever is convenient for you) and make the number of stars/notes directly affect something he likes to do ( 3 stars = 1 hour of video games? tv? computer time?).
I had to install a system like this with my boy and it works great. It took a while until he understood that I will not give in. I had a sulking boy sitting in the corner for a couple of days - but he shaped up real fast.
lego indiana jones game! YAY!
I really like this chart system because it helps me to stay calm in edgy situations. I don't have to yell or punish him right then and there when I am angry at his mouthy response ( -which does not work anyway) I just hand out a note. He keeps going I give him another. The punishment comes with knowing that now he won't be able to play his game later.
He has now grasped the concept that if you want something you got to work for it. He understands cause and effect of his behavior and in the mean time he practices being nice and polite.
we all win!!
lol
This system ONLY works if it is done in a very loving and consistent basis!!
This brings me to your adult relationship. NO ONE should ever ever hit a child. It teaches him the absolute opposite of what you want him to learn.
But:
She is just frustrated and has not experienced living with a little king. She probably feels threatened by his status with you, and it drives her crazy to be disrepected like that. I totally understand!! But if you love her give her time. Don't throw away a thing that is good for you. You have been changing your life to please your child. That is not right, and not healthy for your child!
Here you have a perfect chance to teach him that you are the parent, you chose this woman to be your partner, you love her and your child needs to accept this. You can teach him ( lovingly) that a man will protect his wife(woman) from anything - even smart mouthy little kids.
You both need to be kind and firm with him. No yelling, hitting, or fighting.
Your child will respect her when he understands that you are standing by her side. And that you always want the best for him too!
good luck! you got your work cut out for you!!
-C.
...email me if you have any questions:)