Stitch, you and your wife have tried to make amends and keep peace, but now it's time for your brother and his wife to do the same. No way can you allow someone to disrespect your wife, not even a member of your own family, especially when your wife has extended an olive branch. It's just not done. I hope your brother realizes this, and does what he needs to do to make amends with you. But if not, so be it. I speak from personal experience, unfortunately.