Deejay sighed and continued fiddling with his zipper, not making eye contact.

“Well, it’s just that on today’s trip, I started thinking, and uh... Well, you know how sometimes the wheels get turning in my head, and... things occur to me from time to time. Just... you know, random kinda hypothetical stuff.”

Ty raised an eyebrow. “Uh huh...”

“Right, so... Okay, you ever watch the original Star Trek?”

“No.”

“But you're at least vaguely familiar with the show, right?”

“Yeah.”

“Okay. Well, you know how there were all those alien races? But they looked a lot like humans. I mean, obviously they were humans; they were human actors. But on the show, they played aliens. Alien species that at least superficially looked very human. Sure, there's different colored skin and fringes and stuff, but essentially the same biology, same kind of, uh... anatomy...”

“Uh huh...”

They both fell silent for a beat. Deejay sat back further on the couch and idly kicked his legs forward and backward a few times. Finally he turned to Ty.

“So, let's say I’m captain of the Enterprise-”

“No.”

“Come on, you didn’t even let me finish.”

“Are you asking me if it’s cool if you have sex with aliens in our home?”

“Kind of.”

“Then no.”

“Look, I get this is a little out there, but will you at least give it one second of thought? I mean, let's just say hypothetically, I meet some cute young thing on another world, and you know, things start happening-”

“Deejay, you can’t be serious right now.” Ty took off his glasses and rubbed the bridge of his nose. “I'm uncomfortable enough with you bringing random human girls back here. Aliens are out of the question.”

“Why? What’s the big deal?”

“Is that a serious question? What's the big deal if you bring a female of a different species back here for some morally ambiguous anatomical research? No. I’m sorry, but there's just no way.”

“So what if she’s a little different? It's not like she's an animal. She’s still a person, just a slightly different species.”

“Don’t you see? That’s the whole point. Similar as she might be, we're talking about an alien species. That might be acceptable for some sci-fi tv show, or video game, or some creepy fanfic of said tv show or video game, but that's only because they're counting on the audience to not think too hard about it. You can suspend some disbelief for a cheesy romantic sub-plot in a space opera, but putting the idea into practice is a whole other story.”

“Dude, I just think you're making too much of this.”

Ty shook his head in disbelief. “Look, there are much broader implications for what you're talking about here. If we say we're all fine with inter-species relations, it would set a dangerous precedent. If it ever actually came up and I said I was okay with it, it wouldn’t be much longer before you started meeting and experimenting with other alien species, and then who’s to say your tastes wouldn’t become even more bizarre from there? At that point there's no line anymore. Saying it’s okay to go outside your species is like saying bestiality is okay.”

Deejay stared at him blankly and blinked. “Okay, I can't even tell if you're joking right now. Are you seriously making a slippery slope argument? Has anyone ever been convinced by that fallacy in the history of intellectual debate? Dude, I’m not going to get into bestiality just because I like an alien.”

“Maybe not, but that means you still have to draw a line at some point. Hypothetically, if I was ever going to accept the possibility of humans getting romantically involved with alien species, we’d have to have strict rules dictating what species are okay and what species are off-limits.”

“You can’t make any general rules like that. We're talking about the infinite limitless expanse of possibilities throughout the collective multi-verse, dude. There could be all kinds of sapient and humanoid species, in all different shapes and sizes. There's no way to draw a distinct line between what’s acceptably human and what’s not. It's all a gray area.”

“I’m pretty sure I could come up with some decent guidelines.”

“Like what? Give me an example.”

“Fine. For starters, how about nothing that has a tail? I’m sure you can agree that as a well-adjusted adult, you should never under any circumstances engage in a sex act with any species that has a tail.”

“Well, what about those cat girls you see in anime shows? They’re like regular girls, but they have cat ears and tails.”

He held his hands up next to his head mimicking cat ears, as if that somehow helped illustrate his point.

“I know what cat girls are. I shared a room with you growing up, remember?” Ty shook his head at the memories he'd rather not recall. “Anyway, they’re cartoons. They don’t exist.”

“Infinite parallel universes, dude. Even if it's not probable, it's at least possible. So hypothetically, let’s say they did exist. What then?”

Against his better judgment, Ty entertained the idea for a moment before responding.

“I think I'd want to stick by the rule in that case. If they have tails, then cat girls would be off limits.”

“But they’re essentially human. Without the tail and ears, you couldn’t even tell the difference.”

“It doesn't matter. The whole concept of laying down rules like this doesn't work if you're just going to ask for exceptions to all of them. If cat girls have tails, they're off limits, that's it.”

“Will you listen to yourself? You want to discriminate against people based on how long their spine is. I’ve got news for you, dude: all people have tails, just not very big ones.”

“What are you talking about?”

“The tailbone; the small segment of spine at the base of the spinal column that extends just past the pelvis. It's an obsolete remnant of our primate ancestors, but that is still a tail. That's why they call it a tailbone.”

“It doesn’t matter what it’s called. I have a funny bone in my arm, and there's nothing funny about it.”

“It’s funny when you bang it on something by accident and it sends pins and needles all up and down your whole arm.”

“How is that funny? It’s an extremely unpleasant experience.”

Deejay smirked. “I know. That’s why I said it’s funny when you do it. You get all red-faced and start pacing around muttering obscenities.”

Ty facepalmed. “Well great. At least now I know how that video from Thanksgiving got on the Internet. Can we stay on the subject at hand, please?”

He sighed and rubbed the bridge of his nose again, as if that would help relieve the living headache seated on the couch next to him.

“It doesn’t matter anyway. I’ve already made up my mind. I’m not going to set any bad precedents here. No relations outside your species: that’s the rule.”

“Ty, come on. You still haven’t given me a good reason. You’re just being a closed-minded bigot, and dare I say it, a racist.”

“Racist? Are you kidding me?”

“This is no different than people who were against interracial couples. Well maybe that was how we thought about things back in the 20th century, but these days it’s common and acceptable for two people of different racial backgrounds to be romantically involved.”

“Deejay, you’re talking about two completely different things. Racism was wrong because it discriminated against human beings based on where they’re from and what they look like. What we’re talking about here is an inter-species relationship. That’s a big difference.”

“You only say that because it’s not something you’re used to hearing. Species are an artificial construct invented by humans who were just trying to come up with a viable system to classify living things. It's not a law of the universe, it's a cultural norm, just like racism was. Just because you’ve never been romantically involved with a member of a humanoid alien species, that doesn’t make it wrong. Heck, there's even some evolutionary precedent for it.”

Ty raised an eyebrow. “Such as?”

“Well, let’s look at dogs for a modern example: there are all kinds of different breeds of dogs, in all different shapes and sizes. And then you get into wild dogs and wolves; they’re completely different species altogether, and yet they can still breed with domestic dogs sometimes, and no one cares. If a dog and a wolf decide to mate, no one really finds anything wrong with that.”

“They’re dogs; they hump anything that moves. And if they can’t find anything that moves, they’ll just hump inanimate objects. Do you really want to model your behavior after an animal that is physically attracted to an Ottoman?”

Deejay shifted in his seat, pulling his legs up so he was cross-legged on the couch.

“Okay first of all, don’t get down on someone for humping a footstool. We’ve all done a little experimenting in our hormone-fueled teenage years.”

Ty groaned, echoing the sentiment of everyone everywhere.

“Second, you’re blowing this all way out of proportion. This isn’t some slippery slope situation that’s going to end in rampant bestiality throughout the universe. We're talking about just two people who happen to have a slightly different genetic makeup; two people who, unlike you, had the heart to see the similarities in each other instead of the differences.”

As Deejay started in on his rant, Ty began to wonder if they were putting too much thought into this.

“Now, if you can wrap your brain around that,” Deejay continued, rocking forward onto his feet and starting to pace around in front of the couch, “let’s start talking about the real big picture. The solar system we once called home is a finite thing. Sooner or later, the Earth we know and love is going to be destroyed, whether due to natural cosmic phenomena or our collective hubris, and much of the human race will probably go with it. One way or another, it happens in every timeline sooner or later; the Earth has an expiration date. When that apocalypse happens, and only a handful of human beings are left scattered around the cosmos, what do you think is going to happen? They might last a couple of generations by themselves, but pretty soon they’ll have to worry about negative effects of inbreeding. If they really want their race to survive, they'll need a way to ensure their population stays genetically diverse, which means they’ll have to open themselves up to possibilities like what we’re talking about right now. Eventually, human beings will have no choice left but to procreate with alien species to keep from dying off. Adapt or die: that's the golden rule of the universe. I know it, you know it, Vegetable Lasagna knows it-”

“Is that a quote from something?-”

“-And when that day comes, when the survival of the human race is hanging by a thread, just a little spec of intelligent life blowing away in the cosmic winds, when even technology like mine isn't enough to find any more lingering pockets of humanity in the multi-verse to keep this feeble experiment called mankind going any longer, our descendants will have to swallow their pride and accept what limited options they have available to them. And should we manage to find an alien species similar enough to our own that breeding between our races is possible, mark my words, humans will be thankful for the opportunity to keep our genes and our culture alive. That's where we're going. That's the future of intelligent life. As for me, I’m just getting an early start on friendly intergalactic relations.” He grinned. “See? I'm not a monster... I'm just ahead of the curve.”

There was a long silence, before Ty started laughing. Deejay relented and sat back down.

“...Okay fine, that last bit was a poorly misused line from The Dark Knight, but the rest of my point is still solid.”

“I can’t believe you thought I'd buy that. Do you really expect me to believe we're going through this whole debate for the sake of the fate of humanity? Let me guess: on your trip today, you saw an alien with a nice rack, and now you’re trying to come up with an excuse to justify pursuing it.”

“...Well, technically, that's accurate.”

“I guess your canine analogy works better than I thought. You’ll really screw anything that moves.”

“That’s not true at all. I happen to think I have a very normal libido for my age, and not that it's any of your business but compared to average preferences found in university studies and major polling outlets, my sexual interests trend pretty vanilla.”

“How reassuring.”

“Ty, I don’t care how skeptical you are. Look, I'm trying to be understanding toward your weird hang-ups about sex, but if I meet a girl from another world, and we both like each other, and we decide together we want to have a more intimate relationship, as long as we're both into it, isn’t that entirely our business?”

“When it comes to human relations, yes that's the idea…” He pondered that a moment, and cracked a sarcastic smirk. “…Except, if you recall, if one person involved in said relations happens to be young enough to be considered a minor-”

“Ugh, why do you have to keep bringing that up? We were in Rhode Island; the law was on my side. End of story.”

“Sure. The best moral judgments are usually the ones that involve legal technicalities.”

“Anyway, don’t you change the subject now. For this discussion, I'm assuming an intelligent humanoid alien that is able to make an informed decision on her own. Morality and common sense dictate that whatever two consenting adults do in privacy is their business, nobody else's.”

“Alright, alright… I’ll admit you made some half-decent points.”

Deejay perked up in his seat. “Really? So, bottom-line, if I ever want to get serious with an alien, you’re not gonna stop me?”

Ty winced and shook his head. “The whole thing still sounds insane... I don't know, I guess I’d at least give it some consideration.”

“Consideration’s better than nothing. Thanks, Ty. I’m glad we had this talk.”

“Yeah, yeah. Be careful out there, you freak.”

Deejay laughed. “I'll try.”

He started getting up to leave. Before he reached the door, Ty added one last consideration.

“How about this for a rule: nothing that has an exoskeleton?”

Deejay took a moment to imagine how the mechanics of that experiment would work.

“Hmm...” He shrugged. “I could get behind that.”

Ty wasn't sure if that wordplay was intentional. Neither am I.