For me, what took a good while for detachment to start was that Mr J was a super clinger and tried all he could to be close including causing all sorts of problems, including legal ones.
Like Treasur said, it is hard to detach when we are in the middle of things.
I never tried to help him. From the start I told him there was nothing I could do for him. I really couldn't. Mr J had a level of MLC insanity that left it clear nothing I would do would work.
The drug of a MLCer often is not OW/OM, but their MLC lifestyle. That is the case for Mr J. It is his djing/clubbing/MLC lifstyle that is the drug and supply the high. He has many adoring fans that keep the addiction running.
Of course OW was hurtfult and a problem, especially OW2 who took care of the legalities for him. He had a bit of a high with OW1, but it didn't last. OW2 was never much of a high, more the knightess in shinning armour rescuing the poor broken MLCer.
The addiction is usually to what the substance makes a person feel. Or better, to the chemicals released and targeted as well as the changes provoked by those. In the case of heroin the susbstance has severe body consequences making its withdrawal very taxing physically (as well as emotionally and at brain level).
Addiction doesn't just target the brain, it can target the body/parts of the body. We have neurons other than in the brain, we have glands other than in the brain, etc. It can become a real complicated mess.
With OW/OM, the addiction could come, for example, from arguments. Or, while the affair is secret or recently in the open, the chemical cocktail that comes with it. Later on, something else could be leading the addiction. A MLCer could grow to despise OW/OM and stay with them. Some may, and some may not. Think about non-MLC dysfunctional relationships. People can stay in those for many years. I think it is similar with MLCer and alienator.
Sometimes good things fall apart so better things can fall together. (Marilyn Monroe)