Corruption starts to set in her

As a veritable flood of cum is blasted into Morgan's pussy, she's completely lost her mind, begging for more and more even as it gushes out of her sloppy cunt with wet squelching sounds. Eager to watch the climax that's about to unfold, you leave your chair to stand beside the she-demon as she keeps pumping your sister full of her corrupted cum. As you watch, a large brand is slowly fading onto view, etching itself onto the skin of your sister's bloated pregnant belly. It's an inverted pentagram, heavily stylized into a very artsy version of it, but it's clearly reminiscent of your own demonic tramp stamp at the small of your back.

"Orders are orders - Boss wanted all Bravehearts marked and brought to our side, but you're well on your way there, so your sister's next," the she-demon explains after noticing the direction of your gaze.

"Wait, so my sister's baby..."

"Ha, caught onto that, did you? Yes, the corruption is going to affect the baby the most as the weakest link!" she exclaims with a wide, cruel grin."The transformation is already happening in your sister's womb: from an unremarkable human spawn, to an unremarkable imp!"

You gape at the she-demon in shock. The corruption from her cum is basically going to turn your sister's unborn baby into a demonspawn! Turning towards the quivering nude form of your older sister, you watch as the brand on her belly lits up with purple light and starts glowing softly. Another sign of what's truly happening in Morgan's womb. You should feel disgust, you should feel horror and fear for your unborn cousin, hate for what this hung she-devil is doing to your sister... but none of that surges within you.

Instead, you're painfully aware of the arousal that keeps your smaller cock rock-hard as the futanari demon goes about corrupting your sister. You should be doing something to stop the demon from damning your sister, but instead, you simply scoot closer and reach out with a hand to cup the she-demon's large ballsack, enjoying the way the balls clench with each spurt of cum.

"Ah, that feels good," the demon says with a low groan. "You really are enjoying this, aren't you? Who would've thought you'd love to see your sister fucked and your family turned into a demon?"

"Well, in my defense, it's really hot to see her getting fucked by a beautiful demon with a massive horsecock," you reply and she simply laughs with obvious amusement.

"Damn right! You're not half-bad even if you aren't a demon yet, you know? Name's Irnerin. I'll enjoy fucking you sooner or later. Ah, I think I'm done," Irnerin suddenly says as she takes her hung horsecock from your sister's gaping, wet pussy. It's already softening bit by bit, but given the heavy trail of cum still dripping from the slit, you quickly kneel down and take the large head into your mouth and suck, feeling the musky, bitter cum hit your tastebuds before travelling down to your stomach. "Oh, yes, you'll be a great addition to the Underworld," Irnerin says as she pats your head.

Pleased by the declaration, you continue nursing her cockhead for a moment, cleaning her dick of her own juices even as your own corruption slowly grows within you. But then, the demon stops you, telling the show is already starting. With a mouth full of demonic cum, you watch as your sister starts to groan both in pleasure and pain. Confused, you keep watching until it dawns on you what's going on. Your sister is going into labor.

In clear shock, you stand there as what you'd always thought to be a fairly lengthy process is done in less than ten minutes. Having lost her large pregnant belly, your sister Morgan is left panting on the bed while a fully-grown, cum-splattered Imp wiggles for a bit before standing upright, just in time to be snatched up by the more powerful demon. Holding him by the neck, Irnerin dutifully ignores its indignant squeaking.

"The Underworld is chock-full of these little blighters. Bah, what's one more?" she muses, before she gives the imp a look of disgust. "Get lost and start corrupting mortals, shrimp," she orders the little blighter, throwing him out of the window. Then, she turns towards Morgan with a critical look and doing the same, you realize she's already leaving the bed.

"Oh, God..." she groans, hand flying to her stomach, where the demonic tattoo is still glowing brightly. Now that you're taking a good look, her skin's taking on a faint bluish hue by the moment.

"Morgan? Sis, are you okay?" you ask her. There's a bit of sibling concern in your voice - she's your sister, after all - but you won't deny that the biggest reason for your question is curiosity. Does everyone feel the same way as they're being corrupted? Because that's what's clearly happening to her.

Whatever response you'd expected, it certainly hadn't been a wide smile from ear to ear "Okay? Okay? I'm more than okay, little brother! I feel amazing! This stud fucked me like never before!" she exclaims, looking at Irnerin with a lustful grin.

Moving towards the demon, your sister suddenly stops when her steps resonate with a wet squelch on the floor, having stepped on the puddle of blood formed under her husband's corpse. Instead of grief or shock, she simply smiles contemptuously before kicking away his decapitated head with a laugh. "You were always a limp-dicked loser, James, I'll never understand what I saw in you that made me agree to marry you. Good riddance, I've got a much better life ahead of me getting fucked every day!" she says with a sneer, cupping her pussy with a hand before bringing it to her mouth to swallow Irnerin's leftover cum.

"I take it that you're not really mad about your mortal spawn, then?" the demon asks, arms crossed under her large breasts and a smirk tugging at her lips.

"If anything, you did me a favor! There are too many cocks to suck and too many pussies to eat out, I can't worry about some stupid brat! I'll have kids again when I'm turned!"

Irnerin laughs, enjoying the way Morgan brushes off the destruction of her baby's innocent being with a dismissive wave. Then, she points at her soft cock, which your sister takes as her cue to hurriedly go to her knees and place Irnerin's massive soft cock over her face.

"Yes, these are the type of cocks I need! Large and demonic!" she yells, rubbing her face over the demon's rapidly hardening mast before she takes a moment to peer at you over her shoulder. "Well, are you going yo stand there all day? Either come help me with this stud cock or leave!"