In that scenario, the spouse doing the parenting who isn’t a narcissist should divorce the narcissist. Or keep their pants on until the divorce happens.
‘somehow that leads to cheating’ No it does not ‘somehow’ lead to anything.
Either the person is in control of their actions, in which case they should have the self-control to postpone sex at least until divorce process begins, or they are not in control of their actions and are helpless to prevent themselves from sleeping with the other person, in which case they are not the paragon of virtue you paint them to be.
They may well be a better parent than the narcissist, which is why I don’t say custody should be automatic. I am only saying that infidelity should be strongly considered in custody decisions.
In that scenario, the spouse doing the parenting who isn’t a narcissist should divorce the narcissist. Or keep their pants on until the divorce happens.
‘somehow that leads to cheating’ No it does not ‘somehow’ lead to anything.
Either the person is in control of their actions, in which case they should have the self-control to postpone sex at least until divorce process begins, or they are not in control of their actions and are helpless to prevent themselves from sleeping with the other person, in which case they are not the paragon of virtue you paint them to be. They may well be a better parent than the narcissist, which is why I don’t say custody should be automatic. I am only saying that infidelity should be strongly considered in custody decisions.