Chapter 10 Part 1

Serafall Leviathan, former heiress of the Sitri clan and the only female member of the four Great Satans, had a bit of a problem. She was… severely conflicted. It hadn't started out that way. No, when she'd first caught Issei and Sona fucking, she'd been absolutely blindsided, and she'd fled before she could truly get an idea of what was happening. For a few days, 'Levi-tan' had then given her sister some space, happy for Sona, even if she thought it to be a little weird that the straight-laced young woman was willing to share a man with her entire peerage.

Only when she'd peeked in on them the second time, had she realized what was going on, especially as she'd ended up watching this Issei Hyoudou fuck both her darling little sister AND Rias Gremory. From there, things had spiraled more than a tad. She hadn't been sure what to do at first, and the more time she spent watching her sister and the boy with the Boosted Gear and every other girl he decided to fuck go at it, the more Serafall found herself… wanting it.

His dick, to put it bluntly. The Great Satan couldn't help but lust after her own little sister's paramour as they fucked and fucked and fucked. This had blinded Serafall a bit longer, until she'd watched Issei add a nun and Fallen Angels to his growing harem. Only then did it finally fully register with the Leviathan. Her sister had become this man, this dragon's slave…

… And to her shame, Serafall found that to be undeniably hot. It wasn't like there wasn't precedent for it. Dragons were usually not very sexual creatures, but when they'd decided to delight in the pleasures of the flesh, it had been devils they turned to more often than not, millennia before. Devils were VERY sexual creatures indeed, or could be, and they were made of hardy enough stuff that they could survive a dragon's intentions.

The Sitri Clan in particular had long been the gleeful escorts to the world's mightiest creatures. A Sitri could be found behind every great power in history… so long as it wasn't filled with the Light of course. Though, at the same time, more than a few Fallen Angels could attribute their fall to a Sitri disguised as a human, or hell, sometimes not even disguised at all.

Thing was, Serafall wasn't a Sitri anymore, and while she'd had her fun when she was younger, the beautiful 'Magical Girl Levi-tan' had had to give up all that quite a long time ago. She was a Great Satan now, the Leviathan herself. Plus, she was also a TV Star, though that was really her own choice. Still, between her responsibilities as a Satan and her responsibilities as an actress, Serafall had a LOT on her place, and no time at all to properly relieve her frustrations, or slake her lusts.

Oh sure, she masturbated often enough, even more so after discovering Sona and Issei together, and then discovering just how… prolific Issei was, but that wasn't truly satisfying and it never would be, not for a Sitri. Because even if she wasn't a member of her clan, she was still a Sitri, deep down inside. And a large part of her longed to go to that draconic young man and submit to his sexual predations.

An equally large part of her railed against that though, which is what led to Serafall's severe confliction. In point, half of her wanted to go and save her little sister from the perverse debauchery that Issei was putting Sona through, day in and day out. She wanted her sweet, innocent sister back, she wanted Sona to blush red when she came around and try to enforce rules on her that they both knew Sona had no hope of enforcing.

She wanted… she wanted it to be her instead, if Serafall was being honest with herself. In the end though, that was the current state of things for the beautiful, pig-tailed Levi-tan. The female devil was at war with herself, unable to decide between submission and saving the day. Biting her lower lip, Serafall looks about for a moment. She's on set for her TV Show right now, but they're between scenes as some part of production outside of her purview is stalled by some hold up or whatever.

… That means she has some free time, and with her strength, Serafall can go anywhere she wants, anytime she wants. Hm, it's growing late and the evening has come. Checking, Serafall is happy to find that her sister's presence is in the student council room at Kuoh Academy, despite the school day being open. Surely Sona was busy with work regarding her duties as Student Council President. It was the perfect time for her to pay her sister a visit. Perhaps they could talk about exactly what the Sitri heiress had been doing with Issei Hyoudou…

A smile on her face, the Leviathan teleports off the set of her TV Show right then and there, only to appear in a corner of the student council room. She immediately freezes as familiar sounds fill her ears, and her eyes fall upon an equally familiar sight.

"Oh yes, YES Master! Fuck me Master, fuck your little slut as hard as you can!"

Serafall's smile drops, replaced by a blush and wide eyes as she watches Issei fuck her little sister over the Student Council President's very own desk. The young female devil is completely out of her mind with pleasure, her blouse open and her bra pulled down off her small tits. Her skirt is flipped up and her panties are pushed aside. It's clear that he'd just shown up and bent her over so he could fuck her, and Sona had just LET him.

The Great Satan's blush grows deeper still as she imagines what that might look like, the perverse fantasy playing out in her head made all the stronger by the sound of Issei fucking her darling little sister, and the noises Sona is making as she vocally enjoys it. She ponders for a moment, how exactly she was blinded to Issei's presence. In the end, Serafall has to face the cold, uncomfortable truth that her subconscious mind had betrayed her and ignored him.

She HAD felt him here, with her little sister… but the part of her that wanted her to submit to the current wielder of Boosted Gear had kept her other half from truly comprehending it, from understanding what his presence obviously meant. Now Serafall was face to face with the draconic young man's sexual prowess once more, and the pig-tailed Great Satan can't help but squirm as she watches him fuck Sona silly.

Her pussy is wet, and her inner thighs are rubbing together at the sight of Issei's massive member plowing Sona with deep, long thrusts. Her lips part and she pants with need as her hands slowly move to touch her body. At the last second, Serafall stops herself and finds the strength to take back control. Her jaw sets and though the blush remains, she manages to hold onto her anger over what's been done to her precious little sister, even as she balls her hands into fists and stalks forward out of the darkness.

"Sona Sitri! What do you think you're doing young lady?!"

It's her best commanding voice, and even if it's uncharacteristic when compared to what she normally sounds like, it has the intended effect of causing Sona to freeze in place, her head snapping up and her eyes widening at the sight of Serafall in all her pig-tailed, magical girl glory. Issei doesn't necessarily freeze in the same way, but he does slow down a little, even as he looks at her curiously.

"S-Sister! What… what are you doing here?"

Serafall scoffs at that.

"Did you think I didn't know Sona? You need to stop this, right this instant! You are the heiress of the Sitri Family, you can't just allow yourself to become a toy to some boy!"

"Can't she?"

Issei's words are calm, inquisitive as he continues to look at her. Serafall's eyes snap from her little sister to the man fucking her, and she gives him her best intimidating glare.

"You, be quiet."

"No."

Serafall's eyes widen in outrage at that, even as Issei grins sardonically. Belatedly, the Great Satan realizes that he's grown far stronger since the last time she'd checked in on them. Serafall stares at the boy, surprised at just how powerful he feels. Perhaps not powerful enough to beat her… but there's something intoxicating, arousing… alluring about his strength all the same. She finds herself nibbling her lower lip and squirming under his gaze for a moment before she takes back control once again.

"You dare?!"

"Sister… j-just go away."

Sona's voice is a little tired, but ultimately quite clear and concise as she looks up at Serafall with a frown on her face, now that the shock of her presence has ultimately worn off. Serafall matches that frown and gets ready to put her foot down. Literally, she's about to stomp her foot and take matters into her own hands despite her blatant arousal, when suddenly Issei speaks up.

"Perhaps a wager."

The growing tension in the room is partially derailed as sister and sister break eye contact to look at Issei. Serafall misses the knowing grin on Sona's face, staring instead at the shit-eating one on Issei's as he lifts an eyebrow at her challengingly.

"… What kind of wager?"

She's naturally suspicious of course, how could she not be? But she's also intrigued, more than she probably should be…

"Well, your sister here lost a bet with me, and that's why she's mine now… of her own free will of course. I beat her in a chess game, fair and square."

Serafall grimaces at that, knowing Sona's longtime vow concerning a loss in chess, as well as the fact that she'd seen the black King piece knocked over that first day she'd accidentally looked in on the two having sex. But that was supposed to be for marriage, not for sexual slavery or whatever! It just wasn't fair! Scowling and pouting petulantly, the magical girl devil crosses her arms under extremely impressive bust, not even realizing that she was essentially pushing her tits up subconsciously for Issei's benefit.

Issei definitely notices, and his grin grows wider still as he continues on, giving her a half-shrug as he explains the potential wager between the two of them.

"If you can take Sona's place for the night without begging me for my dick by the end of it all, then I'll never touch Sona again."

"What?! Master, no!"

Issei rolls his eyes and grabs a fist full of Sona's hair, pulling her little sister's head back off the desk and forcing her spine to arch as he gives a particularly powerful thrust into the young Sitri Heiress' cunt, drawing a moan from her throat.

"Are you doubting me slut?"

Sona moans even louder when he starts to fuck her with renewed vigor once more, right there in front of her elder sister. Serafall watches on, mouth open but no words coming out, as Issei plows her sister through two more orgasms before finally nutting inside of her. By the time it's over, the Leviathan is blushing an even deeper red than before, and she's more than ready to accept Issei's bet.

After all, he's unknowingly given her the perfect compromise to settle the conflict raging inside of her heart. The part that wants to fuck him will finally get his cock, and the part that wants to save her sister will see to it that Sona is freed from his control. The thought that she might lose, that she might fall to Issei's dick, never crosses Serafall's mind as she sets her hands on her hips and grins widely.

"Hmph, Magical Girl Levi-tan accepts your wager! You just leave So-tan alone!"