Bit of a back story to this.
MIL is staying with us while her kitchen is being refitted. She has been here for 10 days.
We don't have the best relationship, she doesn't really approve of me and has said several things over the years that let me know how she feels. DP has not heard any of this, she is quite clever at saying things when its just her and me. He thinks that I over-react to the things she says when I tell him.
The last 10 days have been extremely difficult for me, I struggle to interact with her, partly because of the things she has said in the past and partly because she can ignore me for 7-8 hours at a time. If I ask her a direct question, she will respond but thats about the total of our communication.
She doesn't really enjoy any of the meals I cook, and will eat the smallest amount but make a big issue out of it iyswim.
So, to the issue in hand. AIBU to want to rip his head off shout at him for going out on the piss tonight, its a 'boys' night out so I'm not invited.
He knows how much I'm struggling with her and he's gone out. He told me to 'let her get on with her own thing' but she hasn't spoken to me since he left at 6pm. She is sitting in my lounge wrapped in a blanket because I won't put the heating on.
I don't know whether to laugh, cry or drink all the 
So, wise mumsnet, AIBU?