Here's what I've observed...
Some men become sort of desensitized to the porn. They need weirder and weirder things to become aroused. My AH just died. I started going through the discs from his digital camera and found things I wish I hadn't. Some downloaded from the internet. Sometimes they were pics he'd taken of friends, (one in particular in a bathing suit.) I have to kind of fill in the blanks, but some pics are of strangers on the street and look like bad surveillance photos.
I now wonder even more the circumstances of losing his last two jobs. Some pics were taken at a place and time of day when AH should have been at work.
And I wonder about that friend in the bathing suit. The pics of her were *not* taken in secret.
And DH had a scrip for Viagra, he wasn't using it with me.
I think I read somewhere that a downward spiral of more perverse taste in porn is common to alcoholics.