system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is actually happening during an orgasm that makes it feel so good?

I get all the chemical stuff, what's the actually feeling that happens. Someone pointed out muscles contracting, is it just muscles that aren't ever used? Could one figure out how to "flex" these on command?
gpt
Endorphins - natural morphine, also produced by strenuous exercise (runner's high).

Oxytocin - not to be confused with oxycontin, oxytocin makes people cuddly and prone to trusting and bonding with eachother.

Prolactin - does a bunch of things in the body including shutting off sexual response for a while so people stop to take a break once in a while.