There’s a scene in one of the Ringworld books where a human wants to rish with a Kzin, but the Kzin exposes his genitals and immediately disabuses the human of the notion that it would be possible. I’m sure that the sufficiently perverse could find a way, but it need not necessarily be as simple as “insert Tab A into Slot B”.
For comparison from another science fiction work, on Babylon 5, the Narn anatomy is never explicitly described, but we do know that G’Kar (who is sufficiently perverse) is able to have sex (and apparently, quite mutually satisfactory sex) with both human and Centauri women, despite Centauri women having six reproductive orifices arranged along the sides of their abdomens.
If humans meet up with sentient aliens, they’ll be declared “people” in the legal sense very swiftly. If they are like us enough to use language and technology, then they are people. Non-human people.
As such, they’ll have the same rights that human people have. “Human Rights” will be redefined as “Sentient Rights” and therefore inter-species relationships will have the same protections that human relationships have. Meaning that humans and sentient non-humans will be able to marry, and (if possible) have children… hybrids… whatever.
Personally, I’m in favour of it, and I’d probably be interested in getting intimate with aliens myself. Why not? That’d have to be interesting at the very least. Hot alien sex? I’m in.
Given past history, where human humans have been declared legally less than human for purposes of either slavery or slaughter, and even today large segments of the human race are still treated as second class people or worse, I wouldn’t be quite that confident… but I would hope you are correct.
Well, I expect us to attempt to impose the Constitution on the rest of the universe once we get the chance. At least the parts with di-lithium crystal deposits. Eventually the locals will figure out how to lay claim to their rights.
I’m not assuming that we’d give them “human” legal status out of niceness and interplanetary solidarity, I’m assuming that we’d give it to them so that trade agreements are binding.
We’re humans: we will want to sell them crappy Planet Earth snow globes and T-shirts. And we’ll want to buy their crappy rip-off items as well. Trade requires legal status, because we don’t want to accidentally agree to sell them Manhattan Island for $24 worth of alien geegaws.
I honestly think that the first people to make a fortune out of alien contact would be lawyers. And once again I am sad that I didn’t go to law school.
It’s rather more likely that we’d have to worry about whether or not they’d treat us like people than the other way around, given that they are the ones who showed up here and therefore have more advanced technology. We aren’t likely to declare a species nonhuman before the law and enslave them when it would be trivial for them to render the Earth into a ball of molten rock.