Before telling you the actual story, I genuinely wish everyone a merry Christmas and happy new year. Please spend your holidays peacefully with your family members. It should be a season of love of joy, and you share irreplaceable bonds with your family members, so treasure the loving moments you spend with them, because sometime you have no idea that a simple word could just completely destroy everything and turn your life upside down. 

So this just happened today. I planned to go to my parents' place for Christmas on the night of the 24th. This has always been the plan from the beginning because I have some other plan on the day of the 24th. But my mother called me this afternoon, saying that I absolutely need to go back tomorrow morning because she has invited my SO's family over on the 24th for lunch. Our families made arrangements about a gathering during the holiday season for awhile now, and I've always been aware of that, but I was never told when the meeting would actually take place, so I thought no time has been set and it would definitely be after Christmas. 

So needless to say I was really surprised and completely incredulous when I heard about this, yet my mom adamantly claims that this plan has already been communicated to me before and it's my problem that I have other plan on the 24th and I need to cancel it. Her claim that I've been told about the gathering on the 24th is categorically false and to be fair outright ridiculous since I wouldn't have made another plan on the 24th had I known and even if my some miracle I've forgotten about the gathering, my SO wouldn't as well, and she also never told me about it! So I decided to text my SO's parents to confirm about this meeting. They first asked me if my parents' are back from vacation, and I replied yes they just got back yesterday. And their response in their exact words was "we can discuss about the gathering after few days of rest". 

So with my presumption that my mother wasn't being honest about the gathering time already set in stone on the 24th, I immediately interpreted this as irrefutable proof that my mother wasn't telling me the truth. So I immediately texted her and said that she was lying, because my SO's parents just said we can discuss about the gathering after they rest for few days of rest. My mother was furious and showed me some old texts, and it turns out they did actually made a plan to gather on the 24th beforehand, but my SO parents thought that maybe they could use a few days of rest after just coming back from a trip, and I misinterpreted that as "there never was a gathering planned". So I was indeed wrong to have accused her of lying. But while I was not at all happy that she's making me cancel my plan on the 24th to attend the gathering with such a short notice, I was not mad and just accused my mom of lying casually like that with zero intention of being mean to her or hurting her feelings. More like sheer annoyance of "why would you come up with this false pretext so I would have to cancel my plan just to come to home with no sight of my SO's family??". This isn't the first time my mother used such a tactic. She once told me they adopted a dog so being the dog lover that I am, I went home on that same weekend only to find they got a ceramic dog...Now I understand a mother wanting to see her son who lives away and doesn't come back home often, but coming up with false pretext isn't honest and hence why I started with the presumption that this is another one of her pretext. 

Now I know seen some families who have really strict rules about what the children can say, with "liar" being the equivalent of curse words that must be never used against another individual, let alone your parents. Although my mom often hasn't been honest in the things she say to me, I've never before called her a liar before and today was the first time. But I never anticipated that she would basically disown me over this. I don't want to get into the details of what she said since this is about whether IATA, but it let's just say that with what she said there's NO WAY I can go back home this holiday season and enjoy spending the time with my family and that what she said is so hurtful and has caused a PERMANENT fissure to form between us. (I always love my father more but my mother and I have never been on bad terms and I do absolutely love her. Being a very sensitive person I never imagine these hurtful words coming out from her, which is why I'm so devastated). 

So I'm emotionally exhausted right now and utterly regretful of this little misunderstanding developing into such a nightmare, but most of all confused at how or why this even happened in the first place. I really want to believe that I've something terribly wrong and absolutely deserve this, but maybe I'm just such an oblivious jerk that I can't even see what's so terrible about what I said.  

So please, by all means share your honest belief and judgement. If this is indeed so bad of a insult I will never ever use this word in the rest of my life against anyone under any circumstances, but I'm afraid that this one-time mistake has just permanently damaged my relationship with my mother. 

AITA?