Hi, Moo, my H had plenty of evidence what I thought of affairs (my reaction to the affairs in his family) - sadly we don't have any control over the issues that go on in another person. Marriages do NOT cause affairs: the internal coping skills of the person choosing to step outside his marriage is what causes affairs.
Basically what happened is I enabled two years of emotional abuse and witness his commitment and devotion to another person which is hurt that cannot be undone. If there is any recommendation I can give you, that is you MUST protect yourself (and remove yourself from his presence).
I think you do have to communicate your boundaries to him. 'This is what I think of betrayal and this is what will happen if I find you have stepped outside your commitment'. You can't do nothing and THEN zap. Speak clearly and warningly of your concerns and consequences, then zap. He might get enough of a fright to stop.
The problem is that once the contact (flirting, letting the other know they are available, finding out the other is available, extreme arousal, sex) has happened, they enter 'lust-crazed dementia'. At this stage you are dealing with addiction as powerful as crack which lasts about 2 years (see above). They become someone you do not recognise. There is NOTHING you can do, not do, say, not say, be, not be; to stop it.
So I would say for your own self respect you need to do two things:
- communicate your boundaries
- set your boundaries (removing him from the home) once you find the OW/proof. This is to protect YOU - I promise you, watching him not care whether you are breathing let alone hurting whilst he is clearly obsessed with another, will strip you of self-respect that makes you doubt you are worth living. Get him out!
There is a fantastic download by Linda J macdonald lindajmacdonald.com called 'what will you become'? She describes this letter as 'a hard-hitting book for people in the beginning stages of an affair who've lost their ability to be objective about the danger of an outside romance. This is my attempt to shake up a hormone-crazed spous and motivate him/her to wake up and smell the coffee before it is too late. Also useful for hurt spouses who want to understand the roles that hormones and rationalizations played in their partner's affairs'.
It is a right kick in the nuts so I hope you confront him before he gets too deep Don't close your eyes to what is happening. I would not wish my humiliation on my worst enemy - and I brought it on myself for refusing to believe that the love of my life would want anyone else.