Pornography was openly used by Dad. Dad encouraged him to develop the same desires and attitudes. Peer influence is a door. The teenage world is full of pornography. Business trips are full of pornography.
Pornography is supposed to be a part of the male experience in our society.
A personal search for the sexual highs portrayed on television or in the movies is a door. There is no realization that these are actors and actresses acting out a script. When these sexual highs are not experienced, the man thinks something is wrong, and that he is being cheated or robbed. Pornography is a part of their life style. They delight in inviting others to join them in their lifestyle.