Make sure each of the grooms men toast your son that evening, with something nice.
Great guy
Can always depend on him
He is totally in love with the Bride
He is not only going to be a great husband, but also great dad..
Make sure these are their own words..explain that you are concerned, that his new mil may not know all of the great things about him, this is a great time to share.
Have your husband explain, or tell a story about how son has expressed hs love of the bride.
Build your son and his bride up, and stay out of the drama.
Always be as sweet and honest as possible and let that woman look like the lunatic she is.
People know the difference. Just hold the curtains back so they can get a good look at it.