I just can't get past the idea that it would be impossible, or even an imposition, to attend my brother's wedding on my second wedding anniversary. It just isn't a god enough reason, in my opinion.
I bet if it was just the wedding on the second anniversary, and it as announced to the LW and her DH after their own first anniversary, it wouldn't have been as big a deal or as upsetting, maybe not at all upsetting.
I think the problem isn't so much the wedding on the second anniversary its the big blow shock of being told. Its both days told upfront and no acknowledgement its a special day. In so many words they were told "hey bro I totally didn't think of you and your less then a year ago wedding that I stood up in and went ahead and co-oped your first two anniversary's with my own wedding stuff!"
I bet if the conversation was closer to "hey we're having an engagement party in May, we so hope you can be there, and then we were planning on May 11 next year for our wedding. We know that's your anniversary and we are excited to share the date with you" the reaction would be different.
Its probably not so much the wedding on their second anniversary, its the two parties on 2 anniversaries and the total ignoring of the anniversarys. Just one event, 2 years later probably wouldn't be a big deal - its not the one bit
that upsetting, its the whole package
that's upsetting. I think its silly to expect the LW to separate the two events when they essentially were mentioned as one big thing.