Disciplining your kid

My SO and i have been dealing with the issue of his daughter not listening to her mom and step dad. She's been throwing fits kicking and screaming refusing to do what she is told. She didnt even want to go home last week. She ended up kicking her grandma in the face while throwing a fit. Her mom asked my SO for help since his daughter listens to us and doesnt do any of that with us. Since she kicked her grandma in the face she was in trouble for the weekend with us since it was our weekend. Her mom picks her up sunday and takes her to the zoo.

Normally it would be ok except thats how her mom deals with everything when daughter doesn't listen. She calls us to be the bad guys and then rewards daughter when she gets back home with her. Im sorry but it is obvious why she doesnt listen to you. You never want to discipline and when you do you cant follow through with it so its a joke and daughter knows it. All i have to say is next time she calls us when daughter is acting up at her house she can deal with it. We've tried to help her out mulitple times with this problem and she continues to make it worse. From now on if it happens on her time its her problem. She will have the bratty side of daughter and we will get the nice well behaved little girl we have raised in our home. It speaks volumes when they have 2 other girls in their home plus daughter and all of them are bratty misbehaved kids in their home. In our home daughter is a complete different kid and we never have issues with her. Our job as parents is to be parents not their friend.