Can someone explain cucking to me?

How is this a real fetish? How broken does one have to be to want others to fuck their wife. Does it come from a place of self hate? I don't understand.

Why is cuckold a fetish? I cannot think of anything worse.

>>1
Porn creates a reward mechanism in the brain, where you see 'visual sexual activity' as the erotic goal to be excited at. So, when a cuck views his wife in eroric acts, he actually views homemade porn and his brains porn-centric reward mechanims activate. Search 'voyeurism' for the specific fetish of watching people being naked or having sexual acts: porn exploits this fetish on grand scale.