With MLC there is a financial component to all this. The MLCer is avoiding their pain. Running behaviour can be all kinds of things. Drinking, drugs, exercise, younger risky activities all in an attempt to recapture their youth. My own W took up obsessive exercising and ride her bike as fast as possible and for rather unsafe lengths of treks.
Affairs are unfortunately very common. Very common - they mean nothing. Let it go. It has nothing to do with or about you - honest.
An other unfortunately all to common behaviour is spending. Most MLCers will spend money, usually far more than they should or can afford. The LBS needs to focus on themselves and their needs. That includes financial protection and security for you and your kids. Watch your accounts and the spending from joint credit cards, accounts, etc...
Also see a lawyer. This is just for information, you do not need to act on anything you learn. However, if things go south quickly you will know your rights, legal options, and what you are facing. Best to have an understanding of where you are before you need it. Do not tell W about your seeking legal advice, she will not understand or believe why you are talking to a lawyer.
Consider all the information you learn and the risks you face. If your particular situation is too great a risk or is already heading in a bad direction treat the financial part as a business deal that’s gone bad. Generally, the advice is let the MLCer do the heavy lifting regarding any separation and such; do not help and do not stand in their way. They own it, you do not want it anyhow, you aren’t to blame, and they usually are not very good at it so it gets slowed down anyhow.
Most MLCer become terrible parents. You need to step up and provide for them; that is not just financial (however you should consider your will along with everything else). You are the sane and stable parent. The rational one. The role model. Be better not bitter.
DnJ
Feelings are fleeting. Be better, not bitter. Love the person, forgive the sin.
