"Cum rot" is a good term.
I've also recently seen "bonerhead" emerge on Ovarit, and I'll never get tired of that perennial favorite from across the pond, "wanker". Seriously, the Brits were right to use that term as an insult.
I also like "pornsick" because it implies a sickness that can be cured. I think that for certain men in the early stages of a neurotic sexual obsession, they can turn it around. If you have autogynephilia or another fetish, you still have agency. You don't have to end up like Kevin or Wedge.