Sibling who has always disliked me invited me [and one son, but not the other] to his only daughter's very grand wedding. Only not to the actual wedding, or the reception, either, just to a disco in the evening... When my son faced this exact issue last year, we decided not to be petty and invited said sibling and family to our wedding- only they were 'too busy' to come. And now they haven't included him in their 'non wedding' invitation.
It's funny how these things still matter...we don't want to spoil their daughter's big day, she is entitled to invite who she likes. It really shouldn't matter...but still, it's hurtful, tricky and potentially embarrassing, whatever we decide. The bride has asked for money gifts- another elephant trap! I'm curious as to how other families have coped with this issue...