Please help me counsel my poor brother who finds himself as piggy-in-the-middle between our DM and his DMiL

[PacificDogwood]

Our DM phoned my DB's MiL to wish her a belated birthday as she could not reach her yesterday.
Whatever happened next, nobody know, but the conversation ended with them having a major fall out as my mum, apparently, critisied my SiL. This is entirely possible and likely as DM and my SiL don't get on.
MiL tell her daughter who tells my DB who tell me .

My nice DB now feels he ought to smooth things over.

I, otoh, being the hardnosed bitch I am, think he should leave well alone and let the two adult women sort it out themselves.

There is of course history behind this, I don't want to dripfeed, but really v boring: my parents don't approve of my DB's choice of wife.

So, Relationship Gurus, what is your take on this? Should my brother try to be an intermediary here or stay well out of it??
Over to you.

I am tempted to show him, not sure yet.

I do have to stop typing, otherwise my marriage will be in trouble...
His is already, for many reasons, as their relationship has been challenging from the very, very start when they first met aged 16 and then remet and married in their late 30s.

You have given me food for thought, so thanks.

Good luck

Right, came onto MN for a bit of light relief (why oh why did I look in this thread then?!), I've had a shitty day myself and need to get to bed pronto, but can't let this go ....

One thing your DB could do is ask his MIL not to repeat any further nastiness from your DM about your SIL. It's just cruel. She is a woman wit MH problems. Asking may not stop it all but it might minimise damage. There is nothing to be gained by your SIL hearing that people don't think much of her - it's likely she already knows. And your bro does have to work hard to redress the balance where poss. Does he care more for his wife's wellbeing or his relationship with his parents? Maybe now it has reached the stage where, as you say, he has to grow some and make a choice. Your poor SIL. I feel so sad for her. If the whole family agrees your mum is a bit of a bampot, and not very nice to your SIL, then why the hell are they all playing her game? Your DM may have depression but that's not an excuse to be nasty to someone else who has MH problems too. I know you feel your DM cannot change her ways but the rest of the family has to find a way to minimise the damage she wreaks.

Can you have a sharp word with your DF and tell him to tell his wife that it's not her business whether she likes your bro's choice of life partner. I know you feel it's not your business but maybe you can contrive to have the subject brought up in aphone call so you can butt in for a few mins only . Yeah, i can quite see why you are glad you are far far away .