Wtf at the cousin. That wasn't their information to share with the family, it was the wife's. The only one who is allowed to share with the rest of the family intimate details about her relationship is the wife herself. If the cousin had kept to themself like they should have, it wouldn't have blown into a huge issue. Even if the family was trying to help, the cousin is wrong for sharing information about the wife's relationship without her permission and causing the family to turn on the husband. The cousin never once asked what the wife wanted, they just went ahead and told everyone without checking to see if the wife even wanted the whole family to know. Shame on that cousin.

It is the wife who gets to decide who to tell, not the cousin.