Thats a very interesting question. I have a penchant for psychology so i will try and distil this. What usually happens is that people watching excessive porn get bored, this boredom causes them to look out for more extreme cases of porn like Femdom, BDSM etc. This does affect thier mental health. Although the research is not perfect, in my opinion it absolutely does affect your view point. Its impossible not to. But many people have the ability to supress this desire when talking to women. So read between the lines, be aware of what you are doing. Excessive porn isn't in itself bad. Just make sure that you dont dive into the pit of extreme because thats one difficult addiction to overcome trust me.