A much nicer Donner party than the famous one. Even if it also involves people being eaten.

Your comrades have already begun a twisted orgy when you enter. Kyle has bent his mother over the back of the chair, and is driving his cock up the now nude woman's ass as she screams in pleasure. Ryan fucks Gwen on a loveseat, while Maddy, Emily and Vicki have dogpiled Peter, the mature succubi sucking his dick and balls as Vicki forces him to eat her cunt. Amanda and Megan stand near by and watch it all while fondling a rather plain-looking brunette, who stares at the degenerate ongoings with a mixture of fear and fascination. You see Greg's dick tent in his pajamas as he takes in the sights, and listens to the frantic cries and moans.

"Yeah, yeah, take it, Mom! Take your son's demon dick!"

"So good, baby! So fucking good! Pound Mommy's ass! Make her your anal whore!"

"Yeah, that's it you little teen skank. You're so wet for me. So fucking wet..."

"Ohhhh! Oh, fuck, yes, OHHHHH!"

"Mmmm, you like that, Pete? You like us playing with your horny young dick?"

"Oh, he definitely seems to guys! The--AHHHH--way he's eating my cunt! Ooooh!"

"Yeah, that's it, Sammi. Watch it all. Watch your family get fucked like a bunch of sick animals!"

"Oh, shit," mutters Greg. "Oh, oh, shit..."

Kristen and Natalie giggle, then lower themselves so they are before Greg's crotch. They swiftly free his dick from his pajamas, and then whistle appreciatively at the sizable member. "Wow, Mr. Donner!" says Natalie. "Nice package!"

Kristen grabs it and begins to stroke Greg's meat. "I always knew he had a nice cock. And it's going to get even nicer." She swallows it whole, bobbing her head on it at a feverish pace. Natalie giggles in appreciation, and then begins to play with Greg's balls.

Ryan turns to the Jennings sisters. "Hey, toss that bitch over here. I think I'll give her a try. See how she compares to her hot little sister." Gwen gives an appreciative moan at that. Amanda and Megan smile and push Samantha towards the hulking incubus, tearing off her clothes as they do so. Ryan takes in the woman's body, licking his lips, as he grabs her arm. "Not bad. Not bad at all. You've got a decent body, Sammi. You really should show it more." He tosses Samantha on top of her sister, who reaches up and kisses her.

"Gwen?" says Samantha, pulling back. "Gwen, what... why...?"

Gwen kisses her again. "Mr. Wynn is just gonna make you feel good, sis." Samantha seems about to say something when Ryan drives his immense cock into her cunt, causing her to scream in a mixture of pleasure and pain.

Greg has watched all this in near silence as Kristen and Natalie go to town on his dick. But at last something clicks. "Ryan? Ryan is that...? What has happened to you?"

Ryan turns to regard his old friend, his cock still plunging in and out of the pussy of Greg's oldest daughter. "I've seen the light, pal. Or maybe the dark is a better way to put it. Whatever the fuck it is, I've seen it, and I'm showing it to your sweet little girls here." Gwen and Samantha are making out now, hands going over each other's curves. Ryan smiles in appreciation, then drives his tail up Gwen's cunt, eliciting another moan and the youngest Donner daughter's eagerly fucking him back.

"How can you do this to me, man?" mutters Greg, clearly trying to play on his former connection to his friend.

"Hey, I am letting you fuck my daughters," says Ryan. "So, it's not like I'm the asshole here. I mean, come on. This is something you wanted, Greg. Yeah, I remember that chat."

Greg bucks against Natalie's mouth. "Wha..? Ryan, that was... just talk. We were drunk, and we just... started talking about how cute our daughters were getting and..."

Ryan snorts at that. "Yeah, again Greg, I remember. And see, here's the thing--FUCK, YES! It was just talk, back in the old world. But in the world that is to come--the world that IS--it is what you fucking do! You will fuck my daughters, and I will fuck yours, and then, then we will each fuck our own daughters." He gestures at Greg's wife, still eagerly her youngest son's dick in her ass. "Trish here is going to be even more gorgeous than she was when you first hooked up! The way Emily is now a fucking sex goddess! And you will love it all! So don't hold back, pal. Just fucking do it. Do it, and be blessed by Mistress Lilith."

Natalie pulls her lips off Greg's cock and turns around, presenting her shapely ass to him. "Come on, Mr. Donner. Put that big thing into my dripping pussy!"

Greg groans and thrusts his hips forward desperately. You let him go and he rushes forward, and stuffs his dick into Natalie's fiendish cunt. Kristen rests her head on her sister's ass, watching the twisted coupling. You go and join Amanda and Megan, rubbing against each other as you watch the debauchery.

The changes happen quickly after that. Trish screams in climax around her son's dick, and then swiftly transforms into a succubus. Her breasts and ass don't so much grow as tighten, staying the same size but turning from flabby and saggy to a pair of torpedo tits and a bubble butt you could bounce a quarter off of. Meanwhile her stomach and waist contract dramatically and the fat and lines melt off her face, leaving her with a dramatic hourglass figure, and a gorgeously youthful appearance. As her horns, tail, and wings appear, she turns to her son. "Oh, baby," she moans. "Thank you so much."

Kyle palms one enormous, perfect breast. "Anything for you, Mama." The pair share a decadent kiss.

On the floor Pete shoots into Emily's pussy as he and Vicki eat out Maddy. He screams as he climaxes and begins to transform into a muscular incubus. Ryan shoots a dual load into Gwen and Samantha's cunts--the pair groan as they cum, and transform into two more gorgeous succubi, Samantha's plain face shifting into a sexy one like her younger sister's. And as he sees all this, Greg cums himself, beginning to shoot his load into Natalie's cunt. Kristen pulls his dick out, having it shoot into her face as it expands, the jism shifting from white to black the entire time. The Wynn sisters coo as Greg becomes a hulking incubus, any doubts he had destroyed as he embraces sin and lust.

The now soulless Greg turns to regard his friend. "Fuck, Ryan, you were right. This is glorious."

Ryan nods, wrapping an arm around Greg's shoulders. "Welcome to the winning side, Greg." He pulls Greg into a kiss as their families cackle and hoot in appreciation.