My relationship ended a couple of years ago. We'd a group of mutual friends. I've continued to meet up with a couple of them socially whom I'm friendliest with, not with the group. They only see my ex very occasionally, with the group. I'd be much closer to these two than my ex. One of them was organising an event recently and she told me a few weeks ago I'd be invited. I never heard any more about it and haven't seen her since she first mentioned it.
Someone else who was at the event told me my ex was there.
AIBU to feel upset at being left out in the end?