Definitely "Killing Time"

The moment I finished talking, Cass went for it. Full sprint, right into Ember's thicc body. Call me a weirdo, but seeing Cass do it, the little tremors and shakes her target does as her eyes flutter open... it's hot as FUCK. "BRITNEY!" Cass bellows, taking full control. "HOW CHANGE-"

"Focus. And like... imagine a butterfly coming from its cocoon. That's how the two of us do it anyway." Britney answers, biting her bottom lip. She thinks it's hot as well?

"Okay..." Cass mutters, closing her eyes. I can't help but gasp and feel more than a little aroused. In a matter of moments, it's done. It's Cass, unmistakably. Except... with Ember's curves on Cass' thinner, taller body. "Holy... it worked!!" Cass shouts, her own voice coming out, staring at one hand as the other rubs and caresses her body. Err... Ember's body.

"What'd it feel like?" I blurt out.

"Like... a really tight rubber glove getting stretched out, I guess." Cass answers, taking a deep breath. "If I leave, what-"

"The body goes back to normal." Britney interrupts. "Unless you've layered it and the layer visible is still in there. Get it?"

"Think so! This-" Cass started, gasping as Britney jumped into her back and disappeared.

"So you technically possessed Cass there?" I ask as Britney finishes seizing control. She nods, brushing some of her silky black hair out of her face. "You said you're dating Ember, so..."

"Bi." Britney answers, licking her lips. "Want me to change Em's face back to hers? Or mine? Or..." She trails off, raising an eyebrow. "Cass' face still?"

"Up to you." I answer, too horny to really care.

Within moments, we're on the bed. Britney's face is buried into the pillow, her hands gripping the sheets as I thrust into her. There wasn't even a need to "warm-up", we were both hot and ready. Although... hearing her moan in Cass' voice is... weird. And oddly arousing, honestly. Nevermind that she looks like Cass. Minus things like this fat ass in front of me!

"MMMNG!" Britney moans, tightening around my member. Wait. Does that mean... "NNNG!!" She moans as I bring my hand down again. Not hard, but enough to hear that sound as that fat ass jiggles. She gets tighter everytime I do it...

Chuckling to myself, I give her ass another slap as I thrust in. Sure enough, she tightens up again, moaning and pulling the sheets harder. That ass... I gotta do it. Besides, I forgot to wear protection.

"Ken? What... AHNNN!" Britney squeals, falling flat onto the bed as I quickly switch holes. "K-Ken, warn me before..." She moans, her words muffled by the pillow as I thrust into her. I can't help but grin as I feel the pressure starting to hit its limit. "P-Pull out, you-" She says. It falls on deaf ears as I tense up, shooting my load inside her ass.

"Round two?" I ask, panting as I pull out. Britney doesn't answer, breathing heavily as she lays there. "I can go round two if-" I start, stopping myself as Cass jumps out. Or... Britney?

"Geez, Ken." "Cass" sighs as Ember's body changes back to normal. "It's Britney, in case you forgot how this whole thing works."

"I didn't." I sigh. "Remember, I-"

"I know, I know." Britney interrupts, squeezing Ember's ass and making her loudly moan. "You said you could do a round two though."

"Meaning-"

"Yep!" Britney chirps, jumping on top of me and disappearing inside as everything goes black...