Early in the book, government agents Sam and Mary go to a purported UFO landing site. The actual flying saucer they see is a fake; but a real spaceship has landed nearby and the aliens from it have possessed the locals. Heinlein, who was starting to put sex and sexuality into his stories, has Mary note that the possessed men don’t respond to her at all after she “use[d] the sweet little bundle of sex routine” (a really Heinlein way of putting it; of course the woman defaults to being sexy, even on the job). They don’t care. Mary somewhat facetiously calls them “harem guards.” She and Sam figure that the men acted possessed or drugged, but as the book goes on, Sam goes back to the “harem guards” description. Makes me -- straight and still with much to learn about the experiences of people who are gay, bi, trans or otherwise non-hetero -- wonder if that was code for something else.
The “harem guards” analogy works all right 60 years ago, not so well now. It’s my experience, your mileage may vary, but if someone’s being sexy around you, even “harem guards” are going to at some level notice it. I‘m a straight guy who can notice handsome men, and of those men I know who are gay, they notice sexy women, too, even if they‘re mainly noticing their charisma. And if you’re gay, you still have sexuality, and you can notice others’ sexuality when it’s occurring nearby. It doesn’t have to be what you respond to, and the more culturally standard forms of sexuality might be so omnipresent that they can become background noise, but sexuality (or, in a real harem guard‘s case, forced asexuality, right?) is there. Which could be a valid way of portraying aliens, and which Heinlein seemed to be trying to do. Any sufficiently advanced technology may be indistinguishable from magic, and any sufficiently non-human sexuality (assuming aliens have sexuality) may be indistinguishable from, I dunno, farts. Or hair-growing, something that just happens without our noticing it.
Making humans not act like humans is tough. I still remember (and wrote about) the bad, overly standard possessed-by-aliens acting in the 1997 TV version of Robin Cook’s Invasion. A perverse part of me wants to see alien-possessed humans show this by doing Silly Walks, or speaking in modem-dial-up noises, but it can be as simple as human-looking alien Ford Prefect (in The Hitchhiker‘s Guide to the Galaxy) never blinking as often as people expect; a tiny, telling detail. Another is Ford’s inability to recognize sarcasm. Maybe he can’t see certain colors or smell certain smells, either, but how do you portray that? We know how humans behave because we see our fellow humans all the time, and we’re always human, too. We can’t stretch our imaginations that much, so language and metaphor stay imperfect. And also lead to me wondering if Heinlein knew much of what gay men may act like, and went to an analogy that seems almost about gay men but not quite, from a time when it was tougher to speak directly about many kinds of sexuality so such speaking had to be even more folded within analogy and metaphor. Heinlein was never perfect at that, but he did try to stretch in how he presented it. Other authors did it better.
Heinlein, to his credit, put in hints that the aliens are ultimately unknowable, and that our human characters (who sometimes are even possessed by the aliens) are feeling their way through the dark without enough knowledge of the alien slugs. He also seemed to be having genuine fun with the story, showing how the possessed humans take over their parts of the world for a time and how non-possessed Americans start wearing little or nothing so others know they‘re not possessed. And as big a sex fan as Heinlein made sure to have a public sex scene. (I figure had he written this a decade later, he would’ve referenced human-slug porn.) Fun book, definitely of its time and of its author, and it made me think enough to write this, so it worked.