"TRANSFORM OR DARE!" Jen bellowed.
"Like, I, uhhhhh, idunno, uh,,,, uhhhh" Erika spat out.
"TOO LATE!! YOU GET BOTH!!" Jen screamed. "For your transformation, first you'll lose your legs! Then you'll walk over to me, and attach your torso to my ass, making me your legs! Then my eyes and mouth will disappear, but I'll be able to see and hear through your head anyway, so it's ok. Also, you won't have control over me, or anything below your waist. You'll be able to feel it, but you will have no control. I'll also be able to control your arms - I'll be able to override your movements, but you won't be able to overrule mine. I will also have full feeling of all of your body, as well. I'll be able to tell where you want to go, though. ALSO, I want my ass to get even bigger, solely to torture you, as it won't be ok to be naked or inadequately clothed, now will it? In that vein, I'll never be able to get smaller, only bigger, and all new fat you accumulate from merely eating will go to me, your ass and legs! I will also be able to get larger by my own volition, but not smaller!"
Jen continued, "You will not be able to hear my thoughts, but I will be able to hear yours, and interfere in them, and think for you! Now, as for your dare, you and everyone else will forget that I ever existed. I dare you to hate your ass, to be embarrassed by it, to wish it was smaller, but also to never think of losing weight, of exercising, to never have the mere idea of not eating at least 12 cheeseburgers a day, or any type of weight loss surgery. Basically, you'll hate it, wish it was smaller, but never be able to actually make me smaller. However, I dare you to never be in poor health, and you will always be healthy no matter what you eat, so no risk of heart attack or diabetes even if you drink 100 sodas a day! You and me both will also never age another day, we're immortal! However, you will still gain the aforementioned weight. I also dare you to try to find a pair of jeans to fit me! You'll have no memory of any of this, and everyone will think it normal! You will know you're not fully in control, but no one else will ever believe you! Hhahaha!" Jen finished, maniacally laughing.
She felt her ass expand slightly again, and then watched as Erika's legs disappeared. Jen sat down, feeling her ass expand on the cold tile floor, as Erika plopped herself down on Jen's behind. The two merged. Jen felt a jolt as she now could see out of Erika's eyes, and looked down at her massive ass, thighs as thick as her shoulders! She then got up, as Erika turned to the door she didn't budge. Jen caught view of their "shared" body in the mirror, and noted how odd it looked - Jen had been almost a foot taller than Erika, and now it really showed. Erika's petite body sat upon the fattest 4 foot long legs she had ever seen!
"Now why aren't my legs, like, working, c'mon you damn things!" she heard Erika think. Jen then felt a sense that she needed to walk to math class, but she was naked! So she decided to reach down with Erika's arm and slapped her fat ass as hard as she could. Erika screamed and jumped, causing further ripples.
"Oh my GAWD! I'm naked, I need some jeans!" Erika screamed as she felt her ass sway and jiggle heavily behind her.