"Tell you what," said Cheryl, as she started to remove her top, revealing a very nice pair of breasts that would soon get better. "I'll keep my promise to you if your brother Joey keeps his promise to me."
"You want a threesome?" I asked, eagerly stripping off what little clothing I had on.
"You better believe it handsome," replied Cheryl, as she reached out to encourage more growth from my rapidly lengthening cock.
"We'll do it, but on one condition," said Kim. I saw her changing, and was getting more aroused by the second, although Cheryl wasn't aware of it.
Yet.
"What is it sweetie?" she asked, as Cheryl leaned forward to lick some precum off the tip of my cock.
"You have to join our pack."
"What?" asked Cheryl, turning to look at Kim. But instead of seeing the human version of my sister laying next to her, Kim was now in her full werewolf fursona.
One paw was playing with her breasts, teasing each nipple into greater hardness after caressing the teat, while a talon of her other paw was gently stroking the moist folds of her lupine vagina, bringing more moisture and pheromones into the air as Kim teased her enlarged clit.
"Oohhh..." moaned Cheryl, as she seductively licked her lips. "If that offer includes a gorgeous fur coat and all the trimmings, count me in!" she declared, positioning herself on all fours as she lowered her head between my sister's now well furred legs and started licking her werewolf pussy.
Kim gently placed a paw on top of Cheryl's head, but her bi-friend needed no encouragement as she eagerly started lapping away at the wet lupine vagina before her.
Meanwhile, no longer able to control myself, I used a sharp talon on my rapidly reformed paw to rip the rest of Cheryl's human clothing off her luscious body. Soon we would be giving her something far better than ordinary humanity as I grabbed her shapely hips and plunged my hard red rocket deep into Cheryl's moist den.
The three of us started moaning in unison, unable to get enough of each other.
Cheryl continued to lap from Kim's furry chalice, unable to sate her thirst, even as Cheryl's own fur began to spout all across her body.
Kim's tail continued to thump against the floor at her side, probably in time with the licks of Cheryl's now longer werewolf tongue, while she now used both paws to play with all her tits.
I thought I had bottomed out, plunging into Cheryl as deep as I could go, until her rear began assuming its new lupine features. As her tail grew against my chest, my cock slid even further into her werewolf cunt until I had this weird sensation that I was now so deep that I had actually penetrated her womb!
Cheryl only paused her lezzie licking of my sister just long enough to raise her now muzzled head and howl in great pleasure as she finished her first transformation and officially entered werewolf-hood.
Kim and I joined her, welcoming our new sister in a joint howl.
Then Kim and Cheryl smiled at each other before they switched places.
Kim proudly presented her ass to me, so I began fucking her from behind while the ladies assumed a 69 position, eating each other's cunt while paws reached out to play with the other's respective breasts.
I had already released several loads of prime werewolf semen into Cheryl, but there was no way I could pass up an opportunity to fuck Kim.
I kept plunging away, thrusting deeper and deeper into my sister's lupine cunt, until the three of us came in mutual bliss once more.
The last thing I remember is passing out between the ladies, as they took turns cleaning themselves and the still very hard cock of their alpha.