Rant !!

Sorry I don't have anyone to vent to so imma do it here 
So my MIL has started spreading rumors that have made my husband dislike my parents -.- it gets me mad the things hes said about them and how he ignores them when they try talking to him. Like theres plenty of things his mother has said to me that I didnt like but I dont act the way hes acting . 
She said she had to " talk to him " so she wanted him to go over. 
Tell me whats so important that he has to go over and she cant tell him on the phone ? He's been there since 5 -.- he usually tells me to go with him but today when I was putting on make up he was like " what are you getting ready for ? " so I lied and said " its cause I hardly wear make up now so I just want to look nice " and before he left he asked me if I wanted to go , I said " idk " because I wanted him to tell me to go but hes like " i'll be back " and it honestly bothered me because we go everywhere together.  He also said he was going to talk to his mom " in private " so I couldnt be there in the room with them. 
In a way i'm kind of glad I didn't have to go over there because I dont want to see her face , because I dont want to be mean ..... yet ! 
I'm scared that she will break us up.
I'm always told to " act mature " how can you act mature with a person like that ? Shes the one that needs to be mature!