O P you have no one to blame but yourself. Let her do it once and she will own in the future.

Perhaps it is because she cares what you think of her and might want to just let loose with out having to worry about keping appearances. She might act differently around her friends and don't want you to see that side of her. Many people live two-faced lives. Or, she's just being a sister. Either way OP, I wouldn't worry about it. Sometimes people need a separation of friends and family. But I agree, how rude of her to kick you out like that.

Siblings *shakes head*

aw sorry op you could join my party if you'd like? !

You should crash it.

**** your sister, you live in there and have every right to enjoy the party.

And?

That's kind of the way it goes at my house too, with my boyfriends little sister being the party thrower.

Call the cops with a noise complaint.

Invited or not, you still live there