The important point was that one diaper per night went to Hailey, whether or not she used it. So as long as she waited to use it until just before she was ready to change out of it, her parents would never find out.
So really, her only concern was ensuring that Erin didn’t realize what she was doing. Wearing the diapers so that Erin didn’t feel singled out was one thing, but using them was something else entirely. Erin might feel that Hailey was mocking her by voluntarily using the diaper when Erin’s body didn’t give her a choice. She was almost certain Erin wouldn’t tell on Hailey for using the diaper, but she didn’t want to risk insulting Erin. For now, it would be best if Erin didn’t find out.
