The title pretty much says it all.

My family does secret santas instead us buying presents for everyone. This year, my mom decided to limit secret santa to people who would actually be in town for Christmas. I thought that she just meant that we wouldn't be including some more distant relatives who live out of state. They haven't always participated. No big deal. Right?
Well, apparently my mom also excluded the sister who wasn't sure if she was going to make it on Christmas Day.
I suspect that this is her way of getting back at my sister for being wishy-washy about her plans (she has to balance things with her husband's family and admittedly tends to spend more holidays with them because it's a shorter drive). At the very least, it was a really good way to ensure that my sister decided not to spend Christmas with us. Nothing is more alienating than being excluded from our
one holiday tradition.
Apparently, my mom's plan was to not tell my sister that we were doing secret santa this year. Except, she neglected to tell me about this plan (too bad! I would have talked her out of it). She also neglected to remember that my sister's twin tells her everything. I imagine that my sister is not going to be inclined to want to spend Christmas with us.

Is it just me, or is my mom being as rude as I think she is?