It's not my fault my sons misbehaved.

When still with Ex, my MiL was firmly on my side, which kept our relationship strong and made Ex aware that his behaviour was not condoned. It didn't affect their relationship though.

Good points from petallus and jings.

What an awful situation for you to be in Kiora. I bet you are livid with him really but want to protect him too!

Kiora I think you have to be very careful here. If you son's marriage breaks up because of his other relationship and you have been seen to take his side, even try to protect him from being hurt by his wife, then your relationship with your grandchildren could be in jeopardy.

Difficult situation. Of course, we usually stick by our children no matter what. However, I can't help wondering what this thread would be like if it was the DIL who had formed another relationship due to being without her husband for a year!

Basically, I agree with jinglbellsfrocks.

I would simply agree with her. You must feel the same. Let her rage. I would definitely join in. You need to take sides and there is only one right side. I hope she still comes to visit.

If she does tell the children you will have to tell them in private that daddy has been very silly but he stills loves them all. And tell them daddy is sorry now.

It's an awful situation for you all.
Have you spoken to your son? I'm wondering why she read his emails. rubylady's advice is very sound, is that a possible route to take?
Whilst not condoning his conduct, a year away from his family must be very hard and lonely.
Thinking of you Kiora x

Can you suggest that the children come to you for half term while she tries to sort out her feelings at home with her own family and friends? That way it will at least get the children away from a very volatile situation currently and give her some head space to think what to do next. Plus, they shouldn't be in the middle of all this when it is so raw.

I would just try to get in touch with your son. He is where your loyalty should lie, even if you are mad at him at the moment. Just say to her that you understand her hurt and you will have a private conversation about it with your son when you are able to reach him but the children are welcome to come anytime she feels the need for some time on her own. And then sit back and leave it to them. If you meddle too much it may come back onto you if they should break up or even if they stay together. It is their decision, let them sort it out.

How bad are the e mails to this other woman? Do they incriminate him to the point of him wanting something to happen with her? How far away is he working and could he get some time off to come home to sort it all out? It really is his problem, he needs to face up to it all now and do the right thing.

Keep strong, for the grandchildren, as I am sure you will, look after yourself and try not to take too much of this on board.

I would not beg her not to tell, it gives her a lot of power in the situation then.
I think you should sound sympathetic to DIL and say you are sorry she feels hurt but suggest that she really needs to talk to hubby about this, as it is really between the pair of them and not you.
I would also suggest that although you know she is hurt and angry involving the children at this stage will not help them and if she tells the children she will be the one to upset them when it might not be necessary.

Good luck! I am sure some others will be able to add something it's a bit late now.

I've talked to her and told her that. farnorth I've listened and been as supportive as I can. But there really isn't a lot I can do. She has a large family and friends who will support her emotionally. I'm also aware that I'm on shaky ground here and worry that I could make matters worse

They were coming here. I'm frightened of begging her I don't want her using my upset to hurt my son. If that makes sense. Along the lines of
"I'm telling your mother she'll hate you for doing this" or " your mother said this" I don't want her to tell the children. I don't want them hurt or worried. The adults can sort themselves out. Families hey (big huff emotion)

If you feel that you don't blame her for being furious, it could help to say so. It might help her to feel less alone with this huge problem that's hit her, and less likely to hit out by telling the children.

Of course you won't want to 'gang up' with your DiL against your son but there's no harm in saying you think he has behaved wrongly, if you do think that.

Could you email her, beg her not to say anything to the children and visit you as planned so you can comfort, advise and support her and make it clear you're not taking sides but want to mediate?

I don't know what to advise. However, when I found out that my husband was actually having an affair I did everything in my power to stop my children [then in their late teens] from finding out, so I find you DIL's need to inflict her pain onto the children worrying. You say he's working abroad; if he's doing so for financial reasons they must have realised that, by doing so it could put a great strain on their marriage? She needs to calm down and talk things through without telling the children.