I don´t know if she should have been more aggressive instead of subtle, or he should stop putting her on a pedestal of purity.
But their relationship right now is based on misunderstandings and superficiality, if they aren´t able to connect their feelings, they won´tt have a future.
It is because the mother allows that behavior, that her husband does, because the mother doesn´t want him to leave, and he knows it and takes advantage of it.
If one day your boyfriend or husband is with another woman (In "that" way), and you discover it, don´t let it go with a "It's in the nature of men", "If I endure I protect the home", and so on (They're just excuses to give you a martyr-type satisfaction).
They only do it because they think that it is normal in their nature (Like a game), that it can´t be avoided, they know that the woman will depend on them, and she won´t want to abandon them even if he makes her things even worse, because he makes her believe that she can´t live without him, and it becomes a "If you can´t stand it, I'll leave, and you'll be left alone."
You have to make it clear that you won´t endure that kind of behavior, and disrespect, and that it has completely broken your confidence.
You don´t have to be dragged by that kind of man, you must to leave him, and make it clear that you don´t need that kind of man in your life, even if it means living your life without him, that you were born without him, lived before know him, and you can continue living without him.
Only then, that type of men realize that what they are doing is wrong.
And they too can be abandoned.
And the last and most important thing, is because someone has betrayed you, does not mean that everyone, or the next person you fall in love with will betray you.
If you think that, it only means that the shadow of that man, persecutes you even in the present, and has not yet left your life.
Leave that shadow, and show that you can forget him.
So it's your fault if you can't forget (many people can't) or if you do forget you start to trust the same kind of person again? Sorry, but that's just more victim blaming b.s.
It is not the victim's fault if she/he can´t forget (It is the fault of the one who has hurt him).
In this case the only person who is blaming the victim is oneself (or you).
Of course it is difficult to "forget" or "graduate" from a bad relationship or traumatic love experience, and in the worst cases there are people who commit suicide.
This is like the wound of an accident, you can´t blame a wounded person because it takes a long time to heal, just help her/him in whatever is possible within your reach, but it is not good to let that person think that she/he will never be cured in her/his life, shes/he will need people who remind her/his that this wound may disappear over time, that her/his are not alone, and that their life continues.
But what the victim most needs is to recover himself, to recover the person who was before that bad experience,
If in the worst case she/he doesn´t forget, at least she/he resorts to continue living his life.
But never make her/him believe that she/he can´t survive that experience.
It's the worst you can do.