This is an English translation of the original Japanese novel, processed through a translation tool.
There may be some inaccuracies.

Link to part 2
https://privatter.me/page/67d4f765cfec5

To account for the risk of a third party accidentally seeing the contents, they decided to watch the video in Lucifer’s room.
Lucifer cast a spell to ensure no one else could enter. With another wave of his staff, a bolt of light streaked toward a corner of the room. Alastor followed it with his eyes, and from nowhere, a tacky apple-shaped television materialized. Lucifer grinned, pleased with his creation, then hummed a tune as he slotted the DVD into the attached player and hit play.

Slumping onto a two-seater sofa conjured alongside the TV, Alastor and Lucifer watched as the screen flickered to life.

Alastor hated televisions—and watching anything on them.
But if—just if—this really was a message from their future selves…
He couldn’t say he wasn’t at least a little curious about its contents.

If it turned out to be absolute garbage, he’d make Lucifer buy him three drinks, not just one. That was his plan as he settled in.

The screen lit up as the video began. There they were—Alastor and Lucifer, looking no different from their current selves.

“Okay, camera’s set up about here, right?”
“Um… do I really have to be in this? Honestly, I’m not thrilled about it.”
“Come on… we’re about to start, so don’t complain now. I put up with plenty of your requests, so the least you could do is humor one of my whims without griping.”
“Sigh… fine. I’ve got plenty to say, but I’ll let it slide. I don’t like pain, and arguing would be a colossal pain in the ass.”
“Hey! That’s a loud monologue! I can hear everything!”

In the video, Alastor and Lucifer bickered while fiddling with the equipment.

…Was it Alastor’s imagination, or did Lucifer in the video seem oddly restless?

“…Alright, looks good. How’s your end?”
“Yes, everything’s fine here. Shall we get started, then? We need to properly explain to our past selves what kind of relationship we’ve ended up in. They’ll never keep up with what we’re about to do—or why—otherwise.”

“Got it. Ahem! Uh, a-ah… so, in the future, Alastor and I are lovers—”

“?! Pfft…!!”
Alastor was speechless.
Wasn’t that a bit much right out of the gate? The words bursting from the screen were so absurd he was genuinely glad he hadn’t been drinking anything.

“…Heh… haha…”
“…Lucifer?”
“…Pfft, ahahaha!! I knew it—this is one of those ridiculous videos mocking the past us! It’s gonna be the perfect boredom killer, ha, hahaha!!”

Despite Alastor’s stunned silence, Lucifer clutched his stomach and roared with laughter.
Alastor was glad he was enjoying himself, but it irked him that his concern had been entirely pointless. Worse, he realized he’d briefly taken this dubious video’s words seriously—what a fool he’d been.
He’d been an idiot to care even slightly about this rude, arrogant man. Maybe he’d just laugh himself to death.

“So, uh, we’ve got this… special ‘game’ going on between us. It’s weird, but that’s what makes it so great… haha. Uh… where do I even start explaining…?”
“Haha. Are you nervous? Quit stalling—if you drag this out, they’ll get bored and stop the video.”

“Sorry… uh… it’s a master-and-slave thing… between me and Alastor…”

“What…”

“Hey, did you hear that!? Lovers was hilarious enough, but now master and slave too?? Haha!!! Me and you—like that?? Ahahaha!! Best joke ever!!!”

Lucifer, apparently hitting his funny bone, started laughing so hard tears streamed down his face.
Meanwhile, Alastor found it all infuriating—not even remotely funny, even as a joke.

“Okay… let’s drop the usual way we address each other for this. Lucifer, you’ve got more to tell our past selves about our relationship, right?”
“Al… no, Alastor…”

“…It’s fine. Haven’t things always worked out when you left it to me? You came up with this brilliant idea, and now we’re making it happen, right? I’ll see it through. Go on—talk to the camera.”

“Got it… Sorry, I just couldn’t get started alone. Thinking about it and actually doing it are different—it takes guts. But… if you say it like that, I can let go and trust you. …Thank you…”

With a softened smile directed at Alastor, Lucifer began shedding his clothes.

“…Huh?”

Lucifer, who’d been cackling hysterically, froze as he stared at the screen.
Alastor was no different.

“Lucifer… is this really just a joke?”
“…Y-Yeah… it’s supposed to be…”

…Even Lucifer might be starting to suspect something.
For a video meant to mock their past selves, the future pair on-screen were gazing at each other with startling seriousness.

“Ugh… my hands were shaking so bad I couldn’t get it off smoothly…”

In the video, Lucifer—having taken his time—stood completely bare, letting out a strangely seductive sigh.
It was Alastor’s first time seeing him naked. His sickly pale skin and androgynous frame weren’t human—they screamed something beyond mortal comprehension.

Narrowing his eyes provocatively, Lucifer spoke slowly to the camera.

“…From here on, I’ll become Alastor’s possession… his slave… and let him take me in front of the camera. I want you—our past selves watching this—to witness it… ♡”

“Heh. Declaring yourself a slave to our past selves? How ruinous—exactly the kind of thing you’d love. …But there’s still more you need to say to them, isn’t there?”

“Kuku… Right, like Alastor said. This is all my selfish whim. I’m not being threatened or forced into this by Alastor. I wanted this, and that’s how it turned out. Even this video letter—it’s just for us to enjoy the ultimate pleasure in front of our past selves. That’s all it’s for… ♡”

“…What’s he saying…?”

Even the idea of becoming lovers with the man beside him had seemed absurd—impossible.

…A sexual master-slave relationship.
The future Lucifer willingly submitting to the future Alastor, letting himself be taken.
That’s what the two on-screen were telling their past selves.

“Hey… Alastor… this is enough talking, right? I’m getting really… excited… ♡”
“Fair enough… Shall we let our past selves see every bit of your debauchery? Lucifer, since it’s a special occasion, I’ll let you choose. Masturbating in front of the camera, or servicing my cock—which would you prefer?”

…Hey. What the hell? Don’t just start spouting nonsense.
Forcing perverse acts—both options were garbage.

But the Lucifer in the video accepted this rotten dilemma with an ecstatic expression.

“Oh… you’re letting me choose…? You’re so kind today… I want to suck you, Alastor… ♡ Coat it with my spit… fill my mouth with your cock and work it with my throat… ♡”
“Heh heh, settled then.”

Lucifer beamed happily as he reached for Alastor’s belt.
Undoing the zipper, he revealed Alastor’s still-soft cock.

Alastor didn’t often look at his own member closely, so he couldn’t be certain if the flaccid penis Lucifer was facing was truly his.
…He could roughly guess from the video that it was about the same size as his own, though.

“Mmm… ♡ Smooch, mmmph… ♡”
Unfazed by its lack of arousal, Lucifer gently held Alastor’s cock and planted a tender kiss on the tip.
Then, with fervent lips and tongue, he began oral service to the organ that would soon pleasure him.

“Ahh… ♡ Lick, mmm… ♡ Suck, …ha, mmmph, fuuu… ♡ Mmm… ♡ Smooch… ♡”

The video’s Lucifer made wet, passionate sounds as he gripped the shaft backward, rhythmically teasing the underside.
His tongue slithered along it, occasionally pursing his lips to suck up the leaking precum.
There was no hesitation in his movements—this act had clearly been repeated between them countless times.

…The Lucifer on-screen was so far removed from the one Alastor knew that he could watch it with detached calm.

“Haa… ♡ It’s already so big… ♡ Mmm, nn… haa… ♡”

Confirming the cock had gained sufficient hardness and heat, Lucifer took the head between his lips and slowly welcomed it into his mouth.
Entwining it with saliva, he began working it fiercely with his throat.

“Mmph! Nn! ♡♡ Slurp, gag, slurp, nn! ♡♡ Mmmph, fuu, mmmfuu… ♡♡”
“You’re going at it harder than usual since it’s on camera… You’ll turn them off looking so shameless. Stop for a sec.”
“Mmm… slurp, suck… pop ♡♡ Haa, okay… ♡”
“Heh. No need to look so reluctant—I’ll make you feel good. As thanks for sucking me, I’ll touch you… here.”
“Ahh, oh… ♡♡”

Grabbing Lucifer’s buttocks roughly for the camera to see clearly, Alastor slid his thick fingers toward the pink flesh hidden within.
Two fingers, then three—slipping in effortlessly without much prep, drawing delighted moans from Lucifer’s lips.

“Nn! ♡ …Oh… ♡ Your fingers, inside… ♡♡”

Purring with satisfaction at Lucifer’s reaction, Alastor deliberately worked his fingers harder, making crude, wet sounds echo as air mixed in.
Lucifer’s body was clearly primed.
Just a bit of oral, and he was already this ready.

Alastor mercilessly stirred Lucifer’s insides, moving his arm vigorously to intensify the stimulation.

“Ohh!! ♡♡ W-Wait! ♡♡ Ngh! ♡”
“Stop acting cute. Let me hear your usual filthy, whiny moans.”
“Nooo!! ♡♡ It’s, it’s too much! ♡♡ Haa, my ass, ahh! ♡♡”
“Say it. What’s making you feel good right now?”
“It feels good! ♡♡ My ass, getting wrecked by Alastor, feels so gooood! ♡♡”

What a vulgar display of sex. Alastor had never been interested in carnal affairs in life, and he certainly never imagined he’d end up in Hell watching something resembling himself and a stranger rut like animals.

…Ridiculous.
This was just some imposter’s crude adult video sent to mess with them.
He’d drown it out with liquor later and forget everything.
Surely Lucifer felt the same.
With that thought, Alastor glanced at the man watching beside him.

“…?”

Contrary to his expectations, Lucifer’s face was deadly serious, swallowing hard as he followed the video’s events.
His pale, refined features had gone even whiter.

“Looks like… you’re ready. Lucifer… mind if I enter you now?”
“A… ♡ Alastor… can I talk a bit first…?”
“Go ahead.”

Confirming his master’s approval, Lucifer turned to the camera with a lustful expression.
Though his smile was dreamy and enraptured… his eyes held a cold glint.
A provocative stare, as if taunting the viewers.

“…!”
Alastor caught his breath.
Even drowning in pleasure… the video’s Lucifer maintained a chilling dignity, the air of a superior being.

“Hey… you two should hurry up and join us ‘over here.’ I’m about to get thoroughly ravaged by him… and it’s gonna feel so good. Way beyond anything you’re imagining—dozens of times better… ♡ Heh, watch closely. Watch me shamelessly writhe and moan under Alastor… ♡”

With that, he pulled Alastor’s face close and pressed their lips together slowly.

“Mmm… ♡ Nn, smooch… ♡”
“Hey, I keep telling you kisses are a reward. You’re so impatient.”
“Haa, ah… ♡ My lips were lonely, what else could I do? Alastor… hurry, come inside me… ♡♡”

His entrance twitched invitingly.
Alastor gently supported Lucifer’s body with his arms and tendrils. Grasping his hips to control the motion, he lowered Lucifer onto his cock bit by bit.
The massive organ gradually sank into Lucifer’s depths.

It must’ve fully settled inside—Lucifer’s abdomen bulged in the shape of Alastor’s cock.
Once he’d taken it all, Alastor gripped his waist and began moving him up and down without restraint, as if using him like a toy to pleasure himself.

“Aaaahh!! ♡♡ Hah! ♡ It feels, so gooood!! ♡♡ Ahhh!! ♡♡ The rubbing, wait, I’m gonna, go crazyyy!! ♡♡ Ohh, ohhh, ughhh! ♡♡ Ahh, aaahh…! ♡♡”

The sounds of flesh grinding, skin slapping, breathy gasps, and Lucifer’s low, broken moans pierced Alastor’s ears from the screen like needles.

“Ahh, haa, aaaahh!! ♡♡ No!! ♡♡ Alastor’s too, too good, I’m gonna, feel it so fast, it’s insaneee!! ♡♡ I’m coming!! ♡♡ Coming!! Ngh, ahh, I’m cooominggg—!! ♡♡”

His body arched backward, head tilting as he convulsed in climax.
To ensure his face was visible—“You’ve got to show your orgasm face to the camera properly,” Alastor muttered with a snap of his fingers—black tendrils emerged from off-screen, forcibly holding Lucifer’s head forward.

Tears and snot streaked his wrecked, blissful face as he drowned in ecstasy.

“Haa, ahh… ♡ Heh… ♡♡”
“Hahaha… Your orgasm face—so ugly, so pathetic… and absolutely adorable…”

…Let’s make you fall apart even more for them to see.

After the video Alastor’s declaration, their acts grew even more ferocious.

Twisting his nipples hard enough to draw blood triggered another climax.
A shower of tender kisses around Lucifer’s ears turned into a savage bite on his neck moments later.
Sharp teeth tore into soft flesh, golden blood trickling as Lucifer trembled and came again despite the pain.

Insulted by Alastor.
Struck by him.
Ravaged brutally.
Through it all, the video’s Lucifer kept smiling happily.
He accepted every sensation Alastor inflicted, climaxing repeatedly until his body locked in ecstasy.

“…”
Alastor was speechless at the intense exchange unfolding on-screen.

Eventually, Lucifer writhed and begged deliriously, “No more, I’ll break, I don’t want to feel good anymore, forgive me,” pleading with the master before him.

But Alastor dismissed it as nonsense—“No way, you love this”—and dangled the threat of stopping to coax out confessions of “I don’t really want you to stop.”
Skillfully berating him, Alastor continued violating Lucifer’s body without mercy.

“Lucifer… ready to be honest? You can’t get enough of being fucked senseless like this, right? You love losing your mind to pleasure, don’t you?”

“I love it… ♡ I looove it… ♡♡ A-Aha… ♡ Hah, ahh… ♡ Al… ♡♡ I love being fucked up by Al so muuuch… ♡♡”
“You’re slipping back to ‘Al’ even in front of the camera. I’ll tease you here too—go ahead and feel even better…”

“Ahh! ♡♡ That’s, so gooood…! ♡♡ Ohh! ♡ Nn! ♡♡ It’s coming, coming again!! ♡♡ I’m coming!! So deep, I’m losing ittt! ♡♡ Ahh, ahhh! ♡ Hah, aaaaahhh—!! ♡♡♡”

…The brutal sex continued until Lucifer passed out, completely limp.

As Alastor’s cock was slowly withdrawn from the lifeless vessel that had become Lucifer’s body, a flood of semen—presumably poured inside—gushed out from the gaping hole between his buttocks.

“Ugh…”
Seeing Lucifer’s pitiful state, drenched in every bodily fluid imaginable, Alastor let out an involuntary sound.

“…Oh, right. To my past self: If you’re watching this and still feel the same as I do now—wanting to stay in control, to outmaneuver the man in front of you—don’t waste this gift. I’ve given you your chance.”

And with that, the video cut off.