"What did you have in mind?" you ask, intrigued by Brooke's proposal.
Brooke smiles. "Let's start with something... basic." Sitting on the bed and facing you, while stand facing her, she softly clutches your penis and proceeds to jerk you off. Her hand feels warm, and her hold on you is very loose at first, to ensure your comfort-- so loose, in fact, that you can feel the tiniest bit of friction as her fingers slide smoothly back and forth across your shaft.
"Mmmm," you moan, your heartbeat beginning to quicken.
"You like it?" asks Brooke.
"Ohhh... yesss... me like. Want more," Kira answers in your mind. You feel her contempt for the situation retreating. Just as you and Brooke before her, she is discovering the allure of being a living sexual organ, and her arousal is making her forget about wanting to be human again.
"Mm-hmm," you tell Brooke. "And I think your sister approves too."
With her other hand, Brooke reaches up and lightly caresses your balls. Kira begins moaning as her shaft quickly grows and stiffens. After a few more minutes of Brooke stroking you, beads of precum form on Kira's 'lips'. "Oh, why, dear sister," she says, "you're getting all wet. Allow me to help you with that." Without hesitation, Brooke dabs the tip of your penis with her finger, wiping up the fluid dribbling out of it, and then sucking her finger with delight. You can scarcely believe she just did that. But it's no more than a few more seconds before the beads of precum return. Brooke looks up at you with a wry grin. "Oops. That didn't help much, did it? I'll have to try something else."
"Kira cock. Me want fuck!" says her sister's voice. But you're the only one who hears it.
Still holding your now-erect cock, Brooke gets up off the bed and down on her knees in front of you, and kisses the top of Kira's 'head'. Then her tongue slips out, and you feel it glide across your sensitive skin as she willingly laps at Kira's tip. Kira spasms and moans in ecstasy. Finally, Brooke pops her sister into her mouth and begins sucking, with her tepid tongue dancing along the underside. The excitement weakens your knees, and you find that you're the one sitting on the bed now, as Brooke pleasures you orally-- something that, until now, she has been hesitant to do. Your burning lust has returned, with a vengeance, and with Kira moaning, "More! More! Me cock! Want suck! Want fuck pussy!", it feels like your entire being is pouring into this. Somehow-- perhaps because you and Brooke are both participating in your normal bodies-- this time the encounter feels heightened to you, in a way that it did not during your previous encounters with Brooke serving as your penis. "Ohhhh, Brooke...," you say. "Keep going, baby... this feels... great..."
You aren't sure what Brooke has in mind next, but whatever it is, you feel like something amazing is about to happen...