And so does every humanoid race in the galaxy.

Warning: anatomically-correct language ahead. You have been warned.

I get it. I really do. To judge by the sales rankings of such books on Amazon, apparently a lot of people (women?) like to read books in which the heroine gets carried off by a hunky hero with [red-white-blue-green-orange-whatever] skin. Mayhem ensues. First she hates him, then she loves him, and he falls in love with her, even if his species doesn’t experience love. He is fantastically gentle with the fragile human female and they go riding off into the… er… flying off and living happily ever after to produce lots of little red-white-blue-green-orange-whatever skinned babies.

Um, no. Doesn’t work for me. Because I can’t get my head past the fact that as a human female, I am more genetically compatible with a brussels sprout than I would be with our hunky male alien.

Seriously.

If you put two populations of the same animal on opposite ends of the Earth, add geologic time, and stir, they will diverge and no longer be able to produce offspring together. If that can happen with animals of the same species on our happy little planet where nothing is more than 12,500 miles away, think how unlikely it is that a creature could reproduce with a human if it evolved in a whole different solar system, when the nearest star is 25.8 trillion miles away. And the numbers only get bigger and bigger and bigger from there, until they make your brain explode before you’ve even left our cozy arm of the galaxy.

Still with me? Good.

Now, let’s take a look at our hunky male alien, because that’s the other thing I can’t get past. Why is he humanoid? He could just as easily resemble a starfish. Or a snub-nosed wombat. Or a creature from our most horrifying nightmares. But okay, let’s give it that. It’s humanoid. It’s got two arms, two legs, a torso containing various vital organs, and a head containing a brain. (I don’t want to give it that, because there’s a snarky teenaged girl in the back of my mind screaming WHY??? — but I’ll give it that.)

So — all right, it’s humanoid. Why is it a ‘he’? Why would its species have two genders that correspond perfectly to human male and female? Why would it have genders at all? There are lots of ways of exchanging genetic material that don’t involve the messy business of mating. Perhaps they exchange packets of genetic material and tuck them into a little pouch for later use. Perhaps they parasitize other creatures (YUCK!). So why, oh why, would our hunky male alien have a penis? And not just any penis, mind you, but a beautiful penis, large but not too large to fit in a human female vagina (WHY?), dripping (WHY???), and equipped with a set of dangly testicles (WHY???). A penis that inflates and deflates just like a human male penis does (WHY???) and squirts genetic material (WHY WHY WHY???) at the height of an orgasm of mythic proportions (my mental vocal cords are getting hoarse).

Okay, okay, I’ll give you that. Humanoid AND sexually compatible. (The snarky teenager just started screaming again.)

Why wouldn’t the hunky male alien and the drop-dead gorgeous female human poison one another? First, they stick their tongues in each other’s mouths — never mind why an alien would even think of doing such a thing. But they do. Now, human saliva is very slightly acidic. What if his isn’t? Human saliva could burn the bejeesus out of his mouth. Or, even more fun, maybe his saliva is basic. Mm, fizzy kisses. Come away foaming at the mouth. (The snarky teenager chants, “We know what you’re doing…”)

That’s if the saliva isn’t frankly poisonous to one or the other. Or both.

Things could get even more fun when you go south. Human vaginal secretions are acidic as well (more so than saliva). Imagine our hero’s reaction if his species doesn’t tolerate acid on their skin. I’m female, and that even makes me cringe. But what makes me squirm is thinking about what his genetic material (I won’t call it semen, thankyouverymuch) does to her. It’s vanishingly unlikely to be the same pH as human semen, you know. And you know how women develop a yeast infection when the pH of the vagina goes off-balance?

That’s the cue for you guys to nod and try to look intelligent.

You girls are squirming too. Yeah. Talk about a morning after.

And that, your honor, is why the Tolari turned out to be human all along.

No, these are details that will never appear in any of my stories, but that doesn’t mean I don’t think about them.

Happy Thursday!