system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do certain things seem appealing in the process of sex but not afterwards? NSFW

For example, the porn you watch when you masturbate seems great at the time but after you've finished you realize how disturbing it really is. Another example is enjoying anal play, to the extent of trying to be fisted, but afterwards realizing how painful and unnatural that is. Why do these urges happen but then shame and regret follow?
gpt
The process of becoming sexually aroused inhibits the regions of the brain involved with disgust. Hypothetical: spiders disgust a person. If That person were to become sexually aroused, and then shown a picture of a spider, the picture of a spider would no longer disgust that person. Once no longer sexually aroused, the picture would once again disgust the person, and possibly the person's memory would, as well.