So a friend of mine and I have a lot of mutual friends. There's one person that she really doesn't get on with, and in the past has always said that she's not interested in going for drinks with them.
So I organised some drinks with this person and a handful of our mutual friends who do get on with them. I didn't invite my friend, because I really, really thought she wouldn't want to come, and we have three events planned that she is attending. One of the mutual friends asked me if she should be coming, and I said that she wasn't comfortable around this other person, they said that makes sense. I didn't hide these drinks from her, I mentioned them in passing to her, because, like I say, I didn't think she'd be interested and I thought I was doing the right thing.
Now, the drinks have been and gone and she sent me a message saying that she was really hurt that she wasn't invited, and that I had no right to tell our mutual friend that she was uncomfortable. I was stunned, and horrified, and I apologised to her, and explained what had happened, that I had made a mistake in my assumption about her not wanting to attend. I said I should have checked with her first and that I had never intended to hurt her - it's also very rare that I misjudge a situation so badly. She then proceeded to call me a fucking bitch, and several other choice phrases for the rest of the day, and said that my intentions don't matter, only my actions, which hurt her.
So I'm now hurt and upset, but AIBU to be? I was stupid, but not malicious, and I have apologised profusely. I did say she was acting childishly at one point, because she was just having a go at me non-stop, but am I a bitch?