To all of those that helped and gave me support with regards to the awful situation, Thankyou very much and i need some more advise.
Christmas is Looming (incase anyone hadn't noticed) and i need to tell my DM that i wont be going round on christmas day, Not sure what to say tbh.
The reason i dont want to go round is because i know that i will get a "what is SHE doing here" from my step dad which will just mean me walking out with the DDs and it will upset DD1 greatly and ruin DD2s first christmas, piss DH off royaly and the shit will hit the fan big time.
I always go to see my grandad on christmas day too so was thinking of telling DM that i will just see her there, or alternatively she is more then welcome to come and see us at ours (deluded emotion).
I dont think iabu to not go there when it can cause so much agro but i know she will try and make me feel bad for not going so i need some good defences ready.
To anyone that doesn't know what i am going on about sorry i can give background if needed.