How much of a 'crime' have I committed here?
I'm currently 'on a break' from the woman I am seeing (I am a gay female) because we've been arguing for a while. We wanted to give one another some space, as we've had quite a few anomalous/difficult situations to deal with and just wanted to reconvene once we'd had a think and some time away from one another.
She was aware that this weekend just gone, I had two friends staying over. They have birthdays close together and we'd arranged to go out for some lunch and a few drinks and they'd stay over at mine for the night. She doesn't know these friends, although has met them once, heard about them knows who they are.
A week or so beforehand, one of the friends asked if she could bring a friend with her. I trust my friend to not bring anyone to my house who would cause any sort of issue so I said yes, caveating that one of them would have to take the box room which is perfectly adequate to sleep in but that's about it, It's not got a TV or ensuite unlike the 'main' spare room, but that was my only concern.
Spoke to woman I am seeing on Sunday night once they'd left and she was very angry because I had not told her that this other friend (my friend's friend) was coming to the event/staying over. Kept referring to her as 'some random bitch' and that I should have told her.
The only reasons I hadn't told her were 1) I did not see it as any sort of big deal at all, 2) I have been rushed off my feet with work (I tutor and have just taken on two new sets of students so all the admin and marking and being ultra diligent as they settle in) so this (what I saw as) very trivial bit of information slipped my mind it was literally a 2 min conversation and 3) We are still speaking to one another, but not sharing all details of our days at the moment.
In the main though, I really did not mark it as something important. This lunch out was arranged while we were still very much seeing one another but my girlfriend was never going to be around for it (she didn't want to come anyway) regardless. We obviously don't live with one another. She's really quite angry with me for not telling her. I am trying to see it from her point of view but I am struggling. Can anyone give me their point of view please?