Look, dude, it's not about inherent worth. Framing these discussions in such terms is a rhetorical trick to evade their actual subject matter. The real issue is that being cheated on, of losing "sexual control" over your partner (and that phrasing is another rhetorical trick, a way to disguise the real emotional structure of the desire for fidelity as, instead, some sort of patriarchal construct), is /subjectively/ devastating. It /does/ make you feel diminished as a person. It /does/ make you feel "worth less" -- which is, in fact, essentially the message semaphored by your partner deciding to seek satisfaction elsewhere than you. It is a terrible feeling to be told -- explicitly, or even more horribly, implicitly -- that you are not enough for your partner.

This isn't about sexist, fascist, or racist(???) language. It's not a fiction concocted by the far right. It's about the emotional realities of being a human being -- not some fantasy caricature.

You're right, my phrasing re: "sexual control" is rhetorically unfair, and you're right that it is a horrible thing for those who experience a loss of fidelity with their partner.

But I'm not talking about people who have actually been cheated on. I'm talking about the use of the term as a generic insult, which, if you feel so strongly about how subjectively awful it is, I think you should agree is a petty way to weaponize the term, which is what the alt-right does by calling everyone who they perceive as being weak or having been defeated a "cuck".

I'm sympathetic to your point. But ultimately I gotta disagree with the premise of your argument -- specifically, that the misery of being a cuckold makes the use of the term "cuck" unacceptable. Much to the contrary, I think that it makes the term /suitable/ for many situations -- situations that are, in some way, emotionally analogous. I'm hesitant to make this claim unequivocally -- I can see arguing that the mechanics of the use of the term "cuck" exceed mere metaphor in objectionable ways -- but I think that the ability to speak directly to emotional reality supersedes any such argument.

For the record, I'm not defending the alt-right in any capacity. They're loathsome fascists. And that's key -- the problem is the content of their positions, not the language in which they're expressed.