Alison's got the right idea.

"Well, if you *need* it..."

Alison smirks knowingly as she tosses her shirt aside. She beckons you to approach and you gladly comply. As you near the two girls, Caitlyn leaps at you, wrapping her legs around you and squeezing against your chest. With her pressed against you, you can feel that her body is incredibly light, lighter than a person even her size should be. It almost feels like she's...hollow?

Before you can comment on it, though, you feel her begin to grind against you, and you forget all about her not seeming totally human right now. She touches your face, her hand still soft to the touch, guiding your lips to hers. You kiss her gently, but she forces her tongue into your mouth and moans loudly as she makes out with you sloppily. Between kisses, she bites your lip and you feel her suck at the drips of your blood, her moans becoming louder and more erotic.

Alison, whom you had almost forgotten was there, reaches around Caitlyn's head with both hands and detaches her from your lip. "Now now Cait, if you steal all his blood, he can't take care of us. And that was the idea, remember? Besides..." Alison slides her hand around Caitlyn's waist, then around yours, and down to your butt, pulling you with surprising strength, squeezing Caitlyn between the two of you. "The other way is more fun, and he'll have lots of cum for us. Won't you, John?"

She licks her lips slowly, and you nod, your pants already bulging.

"See?" says Alison. "Now...feed us."