New to This - An English Man In Trouble

[Hadlee58]

Hi Folks,
I hope everyone had a great xmas and i wish you all a happy new year
I have had a great xmas in fact the best so far but as it seems to pan out with me things have hit rock bottom again pretty quickly. We had a fantastic christmas as a family so much that my wife said it had been the best one ever, i have been counting down the days to the new year as i cant wait to put 2013 behind me and had made a commitment to myself that whatever happens this next year will be great, nothing has changed on that front i am still glad to say.
Now for the bad bit.... My wife and i had arranged for a day in the city (just the two of us) and we had such a ball visiting some of the sales and a few pubs and dinner too, we arranged for my parents to have the kids for the day and bring them home around 8pm last night, my dad sent us pictures throughout the day of the fun they were having. Once we were all back at base i went to get the kids their PJ's only to return to find my wife in tears, apparently my D4 had told her that nanna had pushed her onto the sofa at one stage and to not move until she had stopped crying, my son8 hadnt seen any off this but did hear nanna telling her to stay on the sofa until she had stopped crying. My wife was ballistic at this stage spouting real venom to me and my family. I tried my best to diffuse the situation saying that maybe there was an issue with context (my mother in the 40yrs i have known her never once raised a voice to me or my sister whilst we were children and is as placid as you could imagine). Not the easiest time to discuss this (both of us had had a few drinks although not drunk) and i did my best to validate and said we should discuss again in the morning when we could discuss rationally. She opted to sleep on the couch and said there is no way my parents could have the kids again and that in essence i always stick up for them and dont support her and we are through.
My wife has always had a problem with my family nothing they seem to do is good enough for her, she believes they have a favorite in my son and dont give my daughter the same (something i haven't seen) and even questioned the presents they brought the kids for Xmas saying they were rubbish tat, she likes to tell people what to buy them, i believe that people should be able to buy what they like - it doesn't feel right to me telling people what to buy them...
I am never one to shirk a problem and have vowed today that i will speak to them in a tactful way at some stage, i do have some issues in this, my son opened up to me today saying he thought although nanna did raise her voice he thought she was trying to be nice, the flip side my wife asked my D to show her what nanna did and she showed her by pushing one of her teddies. My parents are going away for new year and i would hate to ruin this for them ( in that they have taken this year very badly too) and how you can raise this without making a massive deal out of it is beyond me?
I am sat her tonight feeling pretty calm, reality is my wife has never got to the move on stage and i guess this was inevitable, i am glad i gave it my all though and really cant see a way forward from here, maybe its time i did the right thing and end this toxic relationship for the good of us all.
Thank you all H