I'm sorry if wrong group I don't know where to put this...

Long story short my ex husband's family is a bunch of crazies, and his mother just shows up uninvited to my house to pick up my son.

My son's father doesn't see his son due to alcohol and drug abuse his parents lost custody of him when he was 16 due to his father and brother beating the shit out of him and when he was 6 his mother dropped him and his brother off at a hospital and drove herself into oncoming traffic in an intersection.. So anyways

When my son goes do her house (which I hate) he comes home all winey and cranky and is just nasty to me and his step father for about a week to follow, his therapist says she doesn't recommend him going there at all. But I'm afraid if I don't let him go for a couple hours a couple times a month she will take me to court for grandparents rights.

So anyways she just stopped at the house and goes I'm here to pick him up and I'm going to keep him for a sleep over. I politely said well Id prefer if only for a couple hours so he isn't off the wall for next couple days. He response is don't worry ill put him to bed at 8:30.. How do I put my foot down without loosing my cool. All I want to do is tell at her you crazy bat no... No sleepovers.. Honestly deep down I wish they would just disappear like his father did.. What do I do I'm stressing the hell out and my stomach wants to throw up inside itself... I know put my big girl panties on but it really isn't that simple i have and it just lead to a heated discussion and I'm very non confrontational so ugghh. HELP!!