rdslady,
Yes, I most definitely experienced this with my n xh. When he told me he was leaving for another woman, he also pronounced that he had been using pornography and masturbating for many years as his means of satisfaction, while telling me he had very little interest in sex. He had dumped much of what he had around the house and off the internet before he left, but I still found tapes, dvd's, books, toys, etc. hidden in his closet and had hundreds of web hits recovered. Toward the end of our 22-year marriage, he basically masturbated himself to an orgasm and had to use ed meds to have an erection. There were more disturbing things that happened that I am unwilling to talk about, but you get the picture.
It comes down to their inability to be intimate, either mentally or physically. The woman my xh is in a relationship with now is married and therefore attractive to him because she is not available. Obviously, masturbation is the least form of physical intimacy there is, so very appealing to an n.
Consider yourself so fortunate to be away from this loser. He is pathetic and will never be anything but.
Brigid