You can't change him... It is nothing to do with other women. It is about the difficulty to control himself and find fun from the normal life. His fun is from extreme excitement of secret relationship.It is very similiar as ADDICT.
My ex-hu*****and tried very hard to stop this type of relationship by himself. Generally speaking I trusted him during that time. Then I found out he is depressed, no desire for family life, distant and unhappy. Finally I realized only the secrect excitement will give him the happiness, relax and fun...
Finanlly I realized I got to choose a fun partner with secrect affair to light him on; Or a dead fish... When the secrecty is gone, his desire for the family life is gone as well...
This most likely relate to his childhood and how his father treats his mother...
Learn from my lesson. The sooner you leave, the more happier you will be.
Best wishes and take good care of yourself !