It's my best friends 30th birthday
She is having afternoon tea on Saturday for her close friends and then a party on the night.
She invited my friend (who comes on nights out with us ) to the party on the night.
She doesn't meet my friend alone only with me.
My friend lives 45 mins away from us and 1 hour from party venue and also doesn't know anybody but me and my best friend at this party.
So I said she could stay at my house to save taxi fare and I would drop her off next day.
I've decided I'm just going to go to the afternoon tea and skip the night party - so text friend saying I wasn't going now.
Friend is annoyed saying she can't go without me going as she knows nobody and it's too far for her to get home /has bought friend gift and bought an outfit.
Surely that's not my problem?
And should be up to me if I don't go
Aibu ?