I just got off the phone with Josh (a.k.a. the playdate master). He had brought Z's friend Julia home with her from preschool and after lunch the two of them disappeared upstairs. Josh thought it was a little too quiet up there to he headed up to investigate.
The bathroom door was closed. When he peered in, he saw Z on the potty. She'd pooped and was "practicing wiping" with Julia as audience. Apparently she'd been practicing quite a bit as half the roll was in the toilet.
But Josh--who wasn't always the world's most patient person--cleaned her behind, supervised some very thorough hand-washing and unclogged the toilet without complaint.
Quite a guy!