As you reached to untape Jenny's diaper, your younger sister made a discomforted face.
"Ge... Get me on the toilet. Get me on the toilet now!" Jenny said.
You hastened your efforts to untape her diaper so you could get her on the toilet, but it was a very thick diaper and hard to work with. Jenny let out a groaned and as you opened up her diaper, you saw her messing herself, right then and there. It was already too late.
You felt a little sorry for her, but you also were laughing on the inside. You had always been jealous that Jenny had been born with stronger powers than you, and seeing her naked, humiliated and smeared with her own waste was very cathartic to you... not to mention how much she used to abuse her powers when she was a little kid, which was how she messed up her body and became incontinent in the first place. Of course, she was still your sister, so you still felt a tiny bit bad, but it was also satisfying at the same time.
You decided that the best way to mess with Jenny now would be to talk to her like she's a baby.
"Aw, did little Jenny make some doodies?" You said in a sickly sweet voice.
"Lucy... stop it..." Jenny moaned.
You took it a step further. You began to tickle her little tummy.
"I think little Jenny made some doodies." You said, still in your sickly sweet voice.
Jenny couldn't help but laugh. She was very ticklish, after all.
"Lucy... ha ha... stop it! ...ha ha!" Jenny said.
You went for her underarms. She laughed even more now and started to wiggle her arms to try and make you stop. Then, suddenly, Jenny farted. Now you were the one laughing.
"Oh... oh jeez! That... that was out of nowhere." You said.
Jenny crossed her arms.
"Would you just get me cleaned up already?" She whined.
"Fine, fine." You said.
You rolled up her dirty diaper and threw it away. Then you started wiping her butt with some wet wipes. You were sure to get the urine off of her too. Then, wanting to clean the inside of her butt as well, you wrapped a wet wipe around your finger and put it in Jenny's butt.
"Eek!" Jenny said.
"Just getting the inside." You said.
"Oh... Th... thanks, Lucy." Jenny said.
Once you had that all done, you got out a fresh diaper, lifted up Jenny's butt, and slid it under her. You rubbed her diaper area down with some baby oil, and then sprinkled on some powder, before finally taping her up and checking to make sure the leg holes were tight and secure.
"There you go, all finished." You said, patting her on the shoulder.
You helped Jenny to her feet and gave her a playful smack on her diapered butt. She jumped a little but was otherwise fine.
What do you do now?