I reckon it goes way back to the movements that produced them. My first thought is ayn rand: In 1954, her close relationship with Nathaniel Branden turned into a romantic affair. They informed both their spouses, who briefly objected, until Rand “sp[u]n out a deductive chain from which you just couldn’t escape”, in Barbara Branden’s words, resulting in her and O’Connor’s assent. You can see how “The most rational thing is that I fuck your spouse” would appeal to the less wrong folk. en.wikipedia.org/wiki/Ayn_Rand#Atlas_Shrugged_and…