She does herself.

"Here" Sarah said. "You can put it on yourself." She handed Kirsten the diaper.

She took a while to examine it. It was not like most baby diapers. It was plain and white and obviously much bigger. She realized the padding inside was huge, and probably made for an adult with real bladder or bowel issues.

"You weren't planning on making me use this thing right?" Kirsten asked.

"No, no. That would be way to much for one day. Just wear it."

Kirsten was relieved. "Where can I put it on?"

"Best is if you go sit in it on a hard surface. You could do it on the floor if you want to or on the table."

Kirsten decided the floor would suffice. She spread it out and placed her ass in the center. It was soft, and nice. Like sitting on a cushion of clouds. She pulled the back and front to each other. Now the two sides from the back had to be taped to the front. She tried on side first, and then the next, but the result was not good. It was not tight enough around her. Luckily she was able to undo the first tape again and make it much tighter around her hips.

With the diaper around her butt she stood up and looked down.

"Looks good to me." Sarah said.