MIL and her priorities!

This I agree with

But she may be very wary of seeing you because of her son's reaction to her behaviour and (whilst it's very much not ideal) his current attitude

What a very thought provoking post.

Oh for goodness sake Op, when exactly do
you think your MIL can make herself the priority?! When she’s dead?! She doesn’t exist solely to facilitate others.

Honestly the way we expect women to just give and give and give in this society and always put their own wants and needs on the back burner is so wrong

How old was she?

How much of the life she has left is to be spent grieving and lonely?

Who decides?

I’m sorry some of the responses on here OP are a bit aggressive. You’ve come on here for other peoples perspective - it’s really hard when you’re ‘living’ the situation, and obviously people on the outside aren’t privy to all the facts and issues which have unfolded. I would agree with others that your mil has probably come through a very traumatic period, probably is also now more aware of her own mortality, and wants to do what she wants to do while she can. Not all 60+ people are ready to settle down with a cat and grandchildren, pottering in the garden. The only thing I would be disappointed about would be her embarking on an affair with a married man. That’s got nothing to do with having a hard life looking after an ill partner, and more about her values and morals. Try and encourage your dh to speak with her, and ask him to listen to her, and try to form some sort of a relationship with her again - might not be one he wants, but he doesn’t want to just cut her out of his life. The longer that goes on, the more likely they won’t speak again, which would be sad, and ultimately something he will regret years down the line.

I think you have two separate issues here.
Your DH attitude which you cannot control and your MIL role in your child’s life which you can try to influence.
Maybe she felt judged over the first relationship and therefore doesn’t want to discuss or be open about the second.
You can keep the door open, you can keep sending pictures and messages on WhatsApp, you can issue invites at times she might not be seeing her friend. You can suggest meeting up somewhere that there was not a need for too much conversation, maybe a park. Anything to stop the gulf getting wider, and so you are there for her if this relationship ends badly.

Is there an issue here that you are insecure/peeved that she was more involved with your partner's ex's children? Do you feel second fiddle to her? Does she still see much of her first two grandchildren? Does she still see her ex daughter in law? Was their marriage break up mutual? Did you get together soon afterwards? All these complexities may also be adding to the picture too. Family splits are complicated, especially when children are involved.

How does MiL look at it?

Because he is trying to control her actions

I'm sorry so many have been awful. A view is taken and no matter what the OP says, once it is out there, some MNs run with it despite evidence to the contrary, or just to be wilful and nasty
I hope things resolve soon, but it's going to be difficult for a while. Hug your husband, snuggle your DC, and hide under a blanket tent in the living room!

everyone I know think/thought she was the most amazing, selfless woman, but her priorities are clearly the BF

Yup. Woman found guilty of not putting everyone else's needs before her own. You should definitely cut her off and continue to be a saint yourself.

Bless you, OP, you put a really personal and heart felt post on AIBU, and got the usual AIBU shit show of self righteous and often harsh responses. You obviously care deeply about everyone involved. Please ignore the criticism you've had - everyone has an opinion but not all of them are worth listening to.

For what it's worth, in my view, this is perhaps the only time when an affair would be justified. If affairs are always wrong, should MIL have left FIL to start a new life with the new man? Leaving FIL without her support? Obviously not.

And for those saying "in sickness and in health" - have you personally lived through dementia? Because MIL will have lost the partner she thought the world of a long time ago.

Both MIL and new partner have taken comfort in a relationship with one of the few people who truly understand what they are going through. Their time together will be the one small point of brightness in the otherwise grim reality of their huge loss.MIL may be distracting herself but who wouldn't want to in that situation.

It's going to be awful for your husband who is grieving his dad and can't ever conceive of any kind of replacement. But one of the reasons families often implode after a bereavement is that there is just so much anger floating around looking for a target. None of us are rational after a difficult bereavement, and we take it out on the nearest target - health professionals, siblings, inheritance - it's a minefield.

Often these things take time, but if you can both try and understand her a bit, put any selfish or unreasonable behaviour down to grief, maybe offer an olive branch when you feel able, things might settle down in time. Unmumsnetty hugs in the meantime, it sounds very tough on you.

I know right!

It is NOT a good thing to be selfless! And as such as society realises that the better and women’s lives will get better.

A parent having an affair is of course hard for your DH to come to terms with. Time is probably the only thing that will help.

Caring for someone with dementia is soul destroying, I suspect your MIL is now grabbing life with both hands before it is too late for her too.
I think just do your best to keep the peace OP and let some time pass, things will calm down.

Husband has not shouted at or berated her, he’s leaving her to it whilst he tries to come to terms with all that happened.

And yet you also say “he hit the roof” and it was obviously bad enough for his mother to stop speaking to him, so perhaps your DH needs to take a look at his actions which have contributed to this situation rather than you both continuing to blame his DM.

It was okay for OP’s husband to be selfish, leave his previous partner whom he shared two children with but god forbid a woman ever put herself above other people at any point in her life. 30 years raising a family, then 18 months being a full time carer and even after that, don’t dare do anything to contribute to your own happiness.

This. Unless you have lived with Dementia, 24/7, you cannot understand how bad it gets.

MIL needs her own space for now.

I think you need to leave them both to sort it out in their own way. I agree that it doesn’t sound as though she’s doing anything wrong. It sounds to me as though you were expecting exactly the same behaviour as with her older grandchildren but she’s a different person, she’s older, she’s been through a trauma and it’s absolutely true that sometimes the novelty of grandchildren does wear off a bit. She’s entitled to the life she wants, without any emotional blackmail or guilt tripping.

Maybe agree that you’ll continue to invite her over periodically for the sake of your DC and it’s up to your DH whether he stays, goes, whatever, but that’s for the sake of your DC.

You ( and more so your DH) need to realise that MIL is a human being in her own right and not just a Mum, Grandma and widow.
She has a right to a life now and while it may have been a bit dodgy that she had an affair it sounds like there were mitigating circumstances.
Shes only 60 odd and is entitled to some fun and it would be nice if she spent time with your baby maybe she feels that she wants time off from being a Grandma or whatever else anyone expects from her to do what SHE wants now.
She can't expect you all to be waiting with open arms for her to decide she wants to engage with her more but your DH really does need to get over himself and be happy for her

Sorry to read so many unpleasant responses OP.
It must be very hard for you and your husband.
He has a vision of his mother, his parents relationship and it is now smashed.
He definitely needs therapy, urgently.
He is grieving and it is very hard when one party moves on.
@Ivymom's post among others is great.
Dementia robs all the family, particularly a spouse.
Your MIL has probably suffered greatly emotionally and also to see how mortality can be slowly ripped away from you.
She has likely sought solace to blank out the pain and help her cope.
You sound very nice and the best you can do is ask your husband to get counselling for his very complicated grief.
He probably feels he has lost his mum too, which is doubly hard.
Maintain an open door/open heart policy towards your MIL and hopefully time will heal things.
I would be most concerned about her new partner and being there for her if things go badly for her.
Let her know you are always there for her.
The sooner your husband gets support the better.
Mind yourself too, it sounds very stressful for you.

@ChristOnABike87 Your MIL should be supported with her choices the same way she supported your husband and his children from his first marriage. Didn't you also say previously that your husband believed in " till death us do part".

Sorry you’ve had a hard time on here OP. I understand why you and your husband are upset and think it’s perfectly reasonable for you to want your MIL to have a relationship with her grandchild. While I do think she’s entitled to move on with her life she could have been more discreet about it - it was very quickly made public! And cancelling plans with your DH to see her new BF is incredibly rude and hurtful. Please ignore the nasty posts and take on board the helpful ones. Well done to you for making measured and calm responses when faced with idiots on here x

AIBU isn't the place to post if you're feeling sensitive or you're grieving.

Sons can see their mother's as the Madonna biblically speaking . They can accept more easily their fathers finding happiness again. Its just how it happens sometimes.

I can understand a little of how your DH is feeling as we had a similar situation in our family. DPs were together for nearly 60 yrs and DM nursed DF with our help right to the end. Like every marriage it had its ups and downs and she struggled with nursing him at 85yo, both physically and emotionally. However 3 months after DF died it became obvious she was in a relationship with a widowed family friend. I admit I was shocked and hurt that she could so easily "get over" the loss of my DF (and struggled with this as I came to terms with my own grief) but realised she had done a lot of her grieving when he was terminally ill and he had no hope of recovery. She felt that she needed to grab happiness where she could before it was too late. Sadly she died suddenly a year after DF. You read on here of older men finding love/companionship quickly after bereavement (maybe they can't cope on their own) but of course women do too. Your DM and her DP have bonded through that shared experience of their long term spouses having dementia and all that entails - the physical and mental strain can't be underestimated.

We all look for friendship and support in our life journey. Your DH needs to sit down calmly with his DM and talk through his concerns about their ongoing relationship. Is he worried she's disrespecting his DF, it's too soon after his DF died and she might get hurt? Whatever his concerns he needs to let her know he's still there for her.