I did not do this, my porn and booze were enough for me but I hear the same reports time and time again from the partners on Family & Friends. If you aren't looking at that forum it is a helpful insight into familial dynamics. Here are some of the things I have written in the past to supporters about our destrucive bahaviors including infidelity.
My take on destructive behavior is that it is a vestige of the destructive nature of abuse. Abuse destroys innocence. We make sense of abuse by thinking we were bad, deserved it. It's the only way we can make sense of what has/ is happening. Bad people do bad things. Bad things are destructive. Destructive behaviors build on one another. They become a pattern, a cycle, a way of life. There is no other way known to us but the one destructive way. It is a deeply rooted problem that takes years to ferret out and address.
These behaviors are not sadistic so much as extremely masochistic with unplanned collateral damage. The brain likes patterns good or bad. In our pattern we are self-defeating and mired in failure. Everything good in our lives is undeserved and needs to be ruined. By being abusive we are pushing you away, not to hurt you though that is the result, but to run you off and save you from being anchored to a damaged, unworthy, unredeemable failure. Within this pattern of behavior we don't desrve good wives or nice feelings or anything that adds to the comfort and well-being a healthy human might enjoy. The intense psychic pain that causes this distortion prevents us from truly understanding the ripples of pain we're causing all around. Once that pattern is exposed and the self-defeating behaviors are seen for what they are then the guilt and shame set in. Partners can be a tremendous support by showing forgiveness and acceptance. We push away but secretly we want what everyone wants: a loving, safe place to rest. It's just we've never seen that place and we have no idea how to get there.
I've got a bike you can ride it if you like.
Its got a basket, a bell that rings
And many other things to make it look good.
I'd give it to you if I could -but I've borrowed it.