"Transform or dare?" Cassie said.
Rachel stepped in, and quickly shut the door behind her. She had just a brief second to think before she blurted out, "both."
Cassie looked at Rachel with an almost wicked grin. "We'll start with your transformation first. You will regress into a ten year old girl, who wears diapers all the time. You will never potty train. For your dare, you will forget your old Rachel self, and those thoughts will be replaced by new my younger sibling memories."
Rachel's clothes first disappeared from her body. Then, she started shrinking. Her boobs shrank the fastest, giving her a flat chest. Then her hips disappeared. Before she knew it, she was ten years old again.
Then a thick disposable diaper formed on her. Immediately, it was grew wet. she felt it grow messy too, but she was 'used' to that now.
Some jeans appeared over the wet and messy diaper. Some socks appeared on her feet. Then, a My Little Pony shirt appeared over a training bra.
Then she started blinking as her memories disappeared, and changed. At the age of three she started potty training. She hated it, and quit trying, and got her diapers back. At the age of four, she got her first bike with training wheels. At five years old, her mom tried potty training her again for school. However, that failed too. TI also didn't help that her sister was diapered a lot too.
She looked up at Cassie. Rachel then said...