Hey, guys. I think I figured out most of the biochemistry behind ntr and cuckold fetishes. Basically, how excited you're during sex or masturbation depends on your dopamine (a neurotransmitter/hormone of motivation, novelty, excitement, etc) its quantity in your blood/brain and your sensitivity to it. For this reason we love variety and usually don't fap on the same scene twice, at least not in the short time period, why we seek new girls and situations, etc. The higher quality of partner you have, the more dopamine is triggered to motivate you to mate with them. It also makes you ejaculate faster.
Dopamine's opposite is serotonin, which allows you to be more in control of your urges and to feel more happy "in the moment", it's a neurotransmitter of satisfaction and "enough", it makes you feel secure and think that your life is already great as it is. When your girl (i.e. someone very important to you) have sex with someone else your serotonin goes down rapidly while your adrenaline (a hormone of stress which severely increases your sensitivity to dopamine) raises alongside dopamine and your sensitivity to it, thus making you extremely excited compared to the norm. But if there's TOO MUCH adrenaline, then it triggers your "fight or flight" response, thus making some people extremely agitated in a negative way, which is a very big turn off and makes them literally HATE the mere mention of netorare or cucking.
I guess this is a good example of how flawed human beings are from an evolutionary point of view, after all, wanting your girl to cheat on you is very bad for spreading your DNA. I think there's a reason why most fetishes are related to negative stuff and biologically counterproductive and this is the fact that mild negative emotions increase our sensitivity to dopamine (because we evolved to learn from our negative experience and guess what, dopamine is also responsible for learning). If anyone ever wondered if there's something wrong with you for liking ntr, be rest assured that it's just your brain chimes at work.
There are some interesting benefits to being into ntr/cucking, for one thing, you are no longer so terrified of having a girl cheat on you or break up. You also become more calm in life in general because this regular increase in your adrenaline makes you more adapted to stressful situations.
