Sooo why is R the brides maid an not you? Your family after all... Yes I think you have more than a little reason to not go. Your SIL Shows little judgment in her choice of bridesmaid and friends! Since she is choosing to have this woman at her wedding she is choosing to NOT have you at her wedding.... But then again it is family! Do you enjoy your SIL? Is she a quality person to spend time with. Because if you don't go you could hurt or destroy your relationship with her. You could be the better person by attending and not destroying a future relationship IF she ever matures enough to see her lack of judgment. And again you would always be the better person for it.
Its a hard question! And I wish you luck.
Its a hard question! And I wish you luck.