Haha okay that tracks. I haven't read much Heinlein but I remember being very confused at the end of Time for the Stars when his brother's granddaughter was like "Hi uncle time-dilation with pop-pop's DNA. Welcome back to Earth. We're getting married now."
"Sorry, what?"
"I grew up trading your thoughts. It's not incest if you're psychic."
In half life, in the 90s, I was in an elevator with 2 scientists. I kept them alive because they would randomly heal me between fights. But when the door opened they would really into a laser trip and activate a turret to kill me. Reloaded over and over.
Finally I breast one of them to death with the crowbar.
The other one started cowering and begging me not to hurt him. I felt sick.