My take on pornography is more the libertarian take, but not that it has no effect on some relationships, just that I don't care if it does.

I'm not surprised that it has a negative effect on some relationships because so many relationships are dysfunctional when it comes to communication. Porn can just highlight frustrations sexually in a relationship.

"Why can't we be more like that?"

It shows men (and some women) what they are missing, what they would like to try, and if only one partner is on board its going to cause friction.

But again my take is "so what?". Generally its up to the individual to decide whats important to them and their relationship. Ignorance is bliss but its never pretty.

My wife and I were "on board" in our porn feelings, and we knew this BEFORE we got married. While dating, even before internet porn, we found her fathers stash and she admitted she read the stories and we went threw them together. She picked out some porn we bought soon after we were married (both of us were too shy for a porn store, but the internet was a thing by then), and we have improved our own sexual relationship because we learned a few things about ourselves and each other, because of that porn.

Discovering this AFTER you are married, and then finding out your wife (or husband, I've know a few) are unwilling to try that route, even a little, can obviously be frustrating.

Combine this with the "fattening" of america, especially the women, and the general better shape porn actors are in and it would be surprising if porn didn't cause some dissatisfaction in relationships.

Get over it, hit the gym, learn to give your lover a little of what they want, if you can't compromise on it for whatever reason (and I'm not saying you always have to or should) then you may need to get out of that relationship.