I, too, am going to say that it wasn't necessarily a bad thing discussing it with your mother, unless you knew she was going to automatically side with you. I've discussed with my mother some relationship issues I've had with DF. She does what I would've expected, which is be neutral and offer me some insight from someone with years of experience being married. She never automatically bad-mouthed DF and, if she had, I probably would've rethought confiding in her in the future. However, that would've been the same for anyone automatically taking my side and badmouthing the other party, no matter in whom I am placing my confidence.
With that said, I don't think it's necessarily unreasonable for OP's DF to ask the OP stay home, but I do think it's unreasonable for him to expect her to automatically go with what he wants since he's the one who wants to change his plans. My suggestion for a compromise (since he doesn't want to join her) is that she still gets to spend some time with her family THIS year. They agree to compromise starting next year.
DF and I have family out of the area and, really, none locally (FBIL doesn't count because he spends his holidays with FSIL's family or goes out of town to see his and DF's extended family like we do). DF and I determined long ago to alternate. I started this discussion at the beginning of our relationship so that we wouldn't always be visiting his family and never mine. I also mentioned that I don't always want to be traveling, especially if we are blessed with children and they are still young enough to require a lot of stuff when we travel. I am the one who doesn't always want to spend time with others during the holidays, but I don't hold DF back from seeing his family if he wants to (so he goes without me), which includes him going on his family's annual week-long vacation. I don't expect him to stay home on my account just because I don't want to go. Would I like to spend the time with him? Oftentimes, yes, but I know he would be miserable not being with others just like I would be miserable socializing that much so we...compromise.
I think it's selfish of the DF to expect the OP to not see her family because he doesn't want to go, but I don't think it's selfish of DF to want to spend Christmas at home with her. The holiday is only two months away so I think it's too late to spring this surprise on her for this year and is really unfair. Next year should be the consideration BUT, the following year, he needs to go with her. If she has to stay home so they are together, then the fair compromise is when she goes to see her family, he has to go as well. If he refuses, then he can't expect her to never see her family since there is no compromise then.