There are a few rules in life that you just have to follow, no matter how silly they might seem. One- always tell someone when they have something in their teeth. There might be a split second of awkwardness, but they will thank you in the end. Also- never tell your friend they should break up with their partner because even if they do, they might blame you for how sad they feel. Never fry bacon naked goes without saying, though that one might be common sense.
And finally, don't wear white to a wedding if you're not the bride. It's one of those long-held customs that you just don't touch unless you're specifically asked to. But one mother-in-law either didn't care to adhere to it or was just testing the boundaries with her soon-to-be daughter-in-law. Read on for the story and see commenters' advice on how she should shut this situation down.