Rias’ surprised expression lasts for all of a moment before melting into something fond as she smiles at Issei. Letting out a little sigh, the red head doesn’t even try to deny it. She just nods her head in agreement, glancing to Akeno with clear affection in her voice.
 
“… Yes. I want to split it between Akeno and me. You know me too well, Issei.”
 
He’d hope he did. Sure, Issei might not have known Rias OR Akeno very well before this year, but at this point, he’d gotten intimate enough with both of them. Hell, he’d even fought for them. They were a part of his hoard, full stop, and that came with an understanding of the two Devils.
 
Of course, this means its rather unsurprising, the way Akeno shakes her head and squirms in her hog-tied position. In fact, for the first time since Issei tied her up, she looks like she’s actually struggling to get free. Luckily for him, he’d gone ahead and Boosted the strength of those ropes of hers when he’d first restrained her. She wasn’t getting out any time soon.
 
Boosting things other then himself was a new ability of Issei’s. For the longest time, he had only ever needed to worry about his own strength. Hell, he’d very rarely even needed to rely on the Boosting aspect of his Sacred Gear, because he’d worked so hard to get so strong on a base level. But given the sort of things he found himself fighting these days, well…
 
That said, as Rias looks at Akeno fondly and Akeno struggles ineffectually against the Boosted ropes, Issei blinks, an idea coming to mind.
 
“As you can see, Akeno isn’t too happy with what I want. She thinks I should take it all myself, to give myself the best chance of getting pregnant. But that’s just it, Issei… I don’t think I want to be pregnant, if I can’t share it with Akeno.”
 
The idea is percolating as Issei tilts his head to the side. At Rias’ words, Akeno’s struggles have stopped. She hangs her head, and lets out a low, strangled moan. Obviously, the two Devils have been arguing this for quite a bit longer than Issei has been aware of it. This was always their plan, to get Issei to knock Rias up with the serum from Ravel. Except Rias wanted to include Akeno in that, and Akeno didn’t want to take the chance that it wouldn’t work if they split the serum.
 
Ah, he should probably make sure that was correct, actually.
 
“… Does Akeno want to get pregnant, Rias?”
 
Blinking at that, the red head shakes her head.
 
“O-Of course! She’s just being selfless and self-sacrificing when it comes to me, as usual.”
 
It’s not that Issei doesn’t believe the red head, but more that he wants to cover all his bases, especially if he’s going to go through with this idea that’s slowly building up into the beginnings of a plan in the back of his head. And so, striding over to Akeno’s tied up form, Issei levers a very strong, very intense look her way, pinning her with the weight of his presence yet again before removing her gag.
 
“Answer truthfully, Akeno. Do you want me to knock you up? Do you want me to breed you and Rias together, so you can become mothers side by side?”
 
Akeno’s eyes are wide, but ultimately, she doesn’t stand a chance. She can’t help but tell the truth, no matter how much she might want to try and lie.
 
“Y-Yes… b-but-mmph!”
 
As soon as he gets confirmation, Issei shoves the gag back into her mouth, securing it once more so she can’t spit it back out. Akeno, of course, takes issue with this, whining and whimpering and struggling some more. Issei just smiles down at her before looking to Rias and nodding.
 
“You’re right. She’s a self-sacrificing fool. Hand me the serum.”
 
Rias does so, carefully not looking at Akeno as she hands it over.
 
“I-I should say, Issei… if Akeno is being TOO belligerent… Ravel thought the serum might be able to act as a suppository as well…”
 
That gets a reaction from Akeno, but Issei’s laughter cuts the bound and gagged dark-haired Queen off. He shakes his head, making sure he has both girls’ attention as he holds the serum in one hand.
 
“I don’t think that will be necessary. I’ve got an idea… one that I think will assuage Akeno’s fears. Let’s begin. Boost!”
 
Rias and Akeno’s eyes both go wide, as they watch him begin to glow with power. Issei considers how much he wants to do here… before deciding that three Boosts should be enough. He was already so strong without using the Boosted Gear, that going much beyond that risked his mere presence shaking the house around them apart.
 
“Boost! Boost!”
 
The ground beneath his feet cracks a little bit, and Issei nods to himself before looking to the serum in his hand.
 
“Transfer!”
 
In an instant, all of that power is transferred over to the fertility serum, infusing it and making it stronger by many factors. All of Issei’s strength becomes the serum’s strength, enhancing its properties beyond what it would have originally been capable of. There’s not a doubt in Issei’s mind anymore… this serum WILL make it possible for him to impregnate both Rias and Akeno.
 
Offering the glowing serum back to Rias, Issei nods to her.
 
“Take half. Give Akeno the other half. I trust, Akeno, that this assuages your fears that the serum might not work if split between the two of you.”
 
Akeno, wide-eyed and still gagged, can only nod her head in awe as Rias quickly uncorks the vial and carefully drinks half of it. Then, she moves forward and ungags Akeno, putting the vial to her Queen’s lips. No longer fighting it, Akeno happily drinks the rest of the Boosted substance, and both of them look… well, they’re not glowing with power, but in a way, they are glowing with anticipation, with potential.
 
Issei doesn’t even bother waiting for Rias to straighten up from where she’s bent over tending to Akeno. He comes up behind her, his cock rock hard and all too ready for another round, and he grabs her by her hips. Flipping up the back of Rias’ skirt, he yanks her panties all the way down to her knees, leaving her to squeak and plant her palms on either side of Akeno’s bound, trussed up form as Issei drives into her from behind.
 
“I hope you don’t mind, Rias. You’re just too damn delectable like this. I couldn’t resist.”
 
“N-No… don’t, oooh, m-mind one b-bit! Please, Issei! P-Please fuck me! Fill me! B-Breed me!”
 
Issei grins at that. Because that? That was indeed the plan. With a lustful growl, the Red Dragon Emperor begins fucking the gorgeous Gremory Devil from behind, plowing into Rias with all his might. She moans wantonly as his cock spears into her core, as his balls slap up against her clit and pussy mound with every thrust. He’s none too gentle about it… but then, Rias would probably be insulted if he was.
 
She IS a Devil, after all, and while she may not have it quite as bad as her Queen did, Rias could still be a kinky little bitch with the rest of them. She liked to submit to Power. She liked to be used by a strong man who had earned the right to her. She was also a romantic at heart, of course, which was why her and Riser could never have worked out. But her and Issei? Well, that was a match made in heaven.
 
After all, he would never forget her. She was a treasured part of his hoard, a valued member of his harem, and Issei Hyoudou, Red Dragon Emperor, did not let any parts of his harem waste away. With a lustful growl, Issei continues to pound Rias from behind as she squeals and moans, cumming her brains out on his cock again and again.
 
All the while, Akeno is trapped beneath her Buchou. Forced to watch, hog-tied and unable to escape, as Rias gets plowed silly right on top of her. The gag, however, has not been put back… and so Issei feels a tongue licking at his balls, alternating between his rapidly pistoning shaft and Rias’ clit as Akeno goes to town with what little agency she has in this moment. Heh, trust in the minx to find a way to participate even with her arms and legs literally tied behind her back.
 
The sensations are wonderful, and with a lustful growl, Issei doesn’t hold back. Meaning, when his own orgasm finally arrives, he doesn’t try to keep it at bay. No sir, he cums and cums deep inside of Rias, allowing his seed to explode out of him. He’s tempted to Boost himself in this moment, but while he’s recently gained the ability to transfer his power to items and other people, he doesn’t actually have fine enough control yet to push his Boosts into a specific part of his body.
 
If he Boosted in this moment, he might actually hurt Rias with his new strength, and there would be no guarantee that he would make himself more virile. As it was, he already knew he was virile. The problem fell upon Rias and Akeno, as much as he did not blame them for their nature. In the end, the serum would have to do the heavy lifting.
 
Pulling out of Rias, having creampied her most judiciously, Issei carefully pulls her off of Akeno and sets her to the side to rest. Then, he looks down at the hog-tied Queen and raises an eyebrow as Akeno flushes and wiggles before him.
 
“… W-Well, you m-made me drink half this serum… s-so you might as well put it to u-use…”
 
Issei snorts in amusement at Akeno’s soft tone. The normal caustic girl was nowhere to be found in this moment. The usual sadomasochistic fuck slut was replaced by a shy, quiet… yet eager to be bred young woman. Still, Issei agreed. There was no point in NOT fucking her now, wasn’t there?
 
Reaching down, Issei grabs the hog-tied Akeno by the back of her bondage, lifting her up into the air and spinning her around. She moans as she’s treated like a piece of particularly ornery luggage, Issei’s strength allowing him to one-hand her bodyweight with ease. His other hand comes around under her front to fondle and palm one of her tits. Giving it a good solid grope, he listens to her squeal and shake, her pussy practically squirting already.
 
A moment later, he’s inside of her. No hesitation, no last moment to ask if this is what Akeno REALLY wants. They both know it is, and besides, she already drank half the serum. Too late to back out now, really. And so Issei fucks Akeno upon his cock, sliding her back and forth almost like she’s a compact onahole. That’s exactly what she’s been reduced to right now, a sex toy bound and hog-tied for Issei’s pleasure.
 
And as he fucks her, Issei knows… she’s loving every moment of it. Not just because of her wanton moans and lewd cries. Not just because she begs for more, even as he fucks her and kneads her titflesh with one hand. But also because her pussy walls contract around his cock again and again, spasming and tightening and seizing up as she orgasms along his length over and over.
 
Her pussy juices flow down his shaft, making an utter mess as she cums for him ceaselessly. Eventually, Akeno can’t even muster the words to speak. She’s too busy cumming her brains out, and soon her voice is unintelligible to Issei’s ears. But that’s alright, because HE knows what she wants. He knows what she needs. And he wants to give it to her, just like he gave it to Rias.
 
With a loud growl, Issei yanks Akeno back onto his cock one last time, while thrusting forward with all his might. He penetrates directly into her womb as a result of this, which makes her squeal louder than ever before as the mixture of pain and pleasure takes her over the edge just as he begins to cum. He fills and fills her with his seed, pumping a nice, thick load right into her womb as she orgasms alongside him.
 
If the serum works, then Issei believes he’s bred them both beyond a shadow of a doubt. His efforts to Boost the serum’s effects could not have failed, so the failure point would be with the serum itself. And considering it was experimental, there’s a chance it did not succeed.
 
… But no. Issei feels it in his bones. He believes in his heart of hearts that it DID succeed, that Ravel’s serum worked. And that… that has him thinking, as he pulls out of Akeno and leaves her hog-tied form to rest right next to her Buchou. As the two beautiful girls recover with one another, Issei finds himself pondering. Has he been neglecting parts of his hoard, perchance?
 
-x-X-x-
 
“Azazel’s liaison will be here today, Issei. That means the White Dragon Empress and whoever she’s brought with her will arrive in the next few hours. Shall we make ready for them? Or did you have something else in mind?”
 
Gabriel’s words pull Issei from his pondering thoughts, and he can’t help but smile crookedly.
 
“You know I do, don’t you?”
 
Gabriel smiles right back, inclining her head in acknowledgment.
 
“Of course, beloved. What sort of mate would I be, if I did not know your heart?”
 
Heh. Either way, she was right. Still…
 
“What do you think? Could I get away with insulting them by being busy elsewhere? Would you take over introductions in my stead?”
 
“Ask it of me, and I shall move Heaven and Earth, my love. As for what I think… I think you should follow your heart. Always.”
 
Right. Of course. Taking the Fallen Seraph’s words in, Issei considers his options. He wants… he wants to go see Ravel. But perhaps it should wait. Perhaps he should do the responsible thing, and wait for Azazel’s liaison, so they can all get off on the right foot. Except, Ddraig has been on bad terms with the Dividing Dragon for millennia, so isn’t getting off on the right foot impossible? Might as well make a power move instead… right?