Not the parent, but for me, porn served as a kind of supernormal stimulus. It became difficult to become aroused with my partner when I had a practically infinite variety of virtual women to choose from, doing an infinite variety of things. Quitting porn was one of the best things I did for my sex life.
I hear about this sometimes and I just wonder if the post-nut clarity makes you recoil. If I was finding my partner less attractive to the point of finding it challenging to become aroused around them, it certainly has more to do with them than it does with whatever I am watching.
I’ve never experienced this even in the slightest and I’ve definitely had moments where I was unattractive to my partner and not having sex with them and substituting with porn. It was cause they were being a jerk and I didn’t wanna fuck them. Shocker.
It makes me recoil that I replaced my partner with simulacrum of her.
I've been in situations like the one you describe but this was not that. It's not about attractiveness. A good analogy is that you can sate your sweet tooth by eating certain fruits. But if you start binging candy bars and ice cream, suddenly that pineapple you used to love no longer does the job.