It gets more hits than Netflix, Amazon, and Twitter combined, is the 4th highest "thing" that people search for on Google, and it's possibly ruining relationships.
Of course, now with the seemingly endless porn sites that anyone with a Wi-Fi connection can crawl into, and such titillating titles as "Step Dad Fucks Daughter And Her Friends," the classic "Fucking hot divorced wife with house for sale horny for dick," and the award-winning "Her black stockings make the creampie extra sweet" (hand on the Bible, these are actual titles), one can't blame someone for being drawn into this hyper-sexual world.
It's still horrible for you and possibly damaging to your relationship with your SO, with science to back it up.
Excessive porn use is very similar to that of a drug addiction. While it's not a physical substance, people who watch porn on a daily, and even weekly, basis can find themselves with the same —increased tolerance, the loss of control when around it, the compulsiveness to seek it out, and varying withdrawal effects when it goes away. It's very similar to that of a professional gambler, someone who runs every day or eating candy on a daily basis.
Well, those things don't sound so bad, so what's the problem? The brain is neuroplastic, meaning it can change and respond to external factors. Porn can cause long-term and even life-long nueroplastic effects on the brain if viewed in large amounts. Dopamine, the chemical that is released when you do basically anything enjoyable, is a reward system for things that essentially fuel our survival. This changes our neural connections to drive us to pursue the same activity in the future. When you watch porn your brain releases dopamine to solidify the event, creating a connection with the images. When you're away from the computer those reinforced pathways make you want more and possibly even require it. When you orgasm, even more dopamine is released, creating an even stronger link. It's a feedback loop that becomes very difficult to break out of.
But what about your relationship? How does physical sex become affected when someone watches porn consistently? As your tolerance for certain porn increases, you can no longer become as turned on by reality or normal sex. Your porn journey may have started with a simple "First Blowjob Video," but it compounds until eventually you can only orgasm when thinking about "Little Sister Brutally Fucked and Dominated" (Again, actual title). Your instinctual, survivalist brain does not know the difference between an image and an actual person; all it cares about is prolonging our species. As the great Gavin McInnes once said, "You fool your brain into thinking you're inseminating 10s and then when you're with a real woman your brain goes 'What are you doing with this one broad?'"
The science is still out on exactly how porn affects couples. However, in general, what most studies have found is porn can make you find your partner less attractive, create the inability to orgasm without visual stimuli during sex, or, in extreme cases, erectile dysfunction.
Despite all of these negative consequences, porn should not be banned, annexed, or 100% boycotted. As all things, moderation is key and in some circumstances, it can be beneficial, like long-term couples mutually wanting to add a little spice to their sexual escapades. However, when it becomes a daily habit away from your SO or as a replacement for physical intimacy, it's time to cut back, possibly even cold turkey.
I challenge anyone to go 30 days without porn and see how your life and relationship improves. I'd wager it's not as easy as you think.