[BipolarBob]

Watching porn is a cause of erectile dysfunction because it de-sensitizes arousal senses so that it takes more and more to get excited for sexual intercourse. This happens to porn stars who have to rely on Viagra or penile injections to be able to perform repeatedly day after day. After as few years some porn stars report not being able to have sex again.
To summarize, it ain't good for men. That's besides the moral aspects of it. A moral decline negatively affects an overall sense of well being and self worth. Depression can lead to suicide.

[Nifster]

Porn is degrading to both men and women