Ayn Rand and Nathaniel Branden's break-up.

From Nathaniel Branden's "My Years with Ayn Rand", pp. 344-345 -- the situation is that he never slept with her after her depression that ensued after finishing "Atlas Shrugged", but she still wanted to resume a physical relationship -- he fell in love with another woman (a model like a decade younger than him) and hid the truth from his wife and her, then he told his wife, then he wrote a letter to her spilling his guts, and she felt put out because she always hated her appearance, according to what Nathaniel's wife thought -- and, after an hour of her screaming, she slapped him a couple times, during which he remained silent, and then --

Frustrated by my long silence, Ayn demanded, "Well? Do you have anything to say?"

"I am deeply sorry," I answered truthfully, "for the pain I have caused you."

"Well, I have one more thing to say to you!" Ayn stated. And then she left me her final legacy: "If you have an ounce of morality left in you, an ounce of psychological health, you'll be impotent for the next twenty years! And if you achieve any potency sooner, you'll know it's a sign of still worse moral degradation!"

. . .