Tough one. Sis will understand, but not so much mom and dad. (I can here it now ... "you're own brother couldn't bother coming to your party.")
OTOH, weddings are a single event in people's relationships with each other. Miss it and you'll never get it back.
I'd go to the wedding and then at an appropriate time, I'd call sis from the wedding, apologize personally for not being able to be part of the "surprise" and set up a lunch or dinner to make up for it.
OTOH, weddings are a single event in people's relationships with each other. Miss it and you'll never get it back.
I'd go to the wedding and then at an appropriate time, I'd call sis from the wedding, apologize personally for not being able to be part of the "surprise" and set up a lunch or dinner to make up for it.