He should have at least invited his sister.
Huh-uh. No thanks!
I actually think it was more of a watch-a-movie-have-a-few-beers sort of thing...not exactly a wild party. Hope it was fun...but I'm still ticked off at his taking it for granted that it bugs no one if he changes plans at the drop of a hat - even plans that include other people.
I actually shared an apartment with him for a few months. I'm still amazed we're both alive. I used to come home and be told that he had told people he'd meet with them in ten minutes, and could I give him a ride over...no thought at all that I MIGHT have plans of my own. He hasn't changed much.