This inspires a lengthy recollection regarding my own narcissistic mom who clung to a relationship with my ex #, a man who was totally wrong for me, all the way up until 3 weeks before he was to marry wife #2...something he'd kept under wraps until our divorce was final.
I'd better leave it at that or I will be spilling out my own story in response.
Don't EVEN get me started!!!
The hubby was absolutely right to do what he did.
Tho I myself would probably have read it in silence and then delivered a cold, icy silence as a response. Of course, MIL would then bendt over backward trying to get him to respond to what was in the email. THEN perhaps a response could be "Sorry, mom (or whatever he calls her), that email was addressed to me and it is a private matter. We can talk about it later."
But hubby's choice was just fine.
It was wrong for her to ask him to read it at the dinner table. Typical seriously manipulative narcissist behavior. And if the family didn't like it, EFF THEM. They can go take a flying leap into the nearest large body of water. And take mom with them....