(((Buffalo))) - she's acting out for whatever reason, but she's wrong. Dead wrong. She most likely doesn't want to deal with him and is ticked at YOU because you're not taking him off your hands.
You're doing what's best for you and your son, and you have every right to do that. Meanwhile, HE is acting erratic as is his mom.
I'm sure the things she said and they way she said them hurt, but I'd have to think she's got some serious issues and they are just coming to the surface. All this time, you've had to put up with his stuff...and that was fine with her. Now that you've asked him to leave, she's not getting what she wants and she lashing out at you. He's not getting what HE wants and is doing the same. Sound like a pattern? She may have mellowed, after beating her kids, but she still has some problems.
Keep doing what you need to do for you and your son. If that means not talking to her, do it. If it means not talking to him, other than if it directly involves your son, do it. You don't need this **** and you, most certainly, don't deserve it.
Hugs and prayers,
Amy