1. Emily, my ex would do this. It was a symptom of so many other problems. Leonard has chosen to play stupid here, so you can play along. Yank the sheet off, wake him up, and have him help you make the bed correctly, very slowly and meticulously with a lot of instruction on getting the corners just right. When the bed is made, pull it apart again and have him do it himself while you watch.

The top of the sheet has a wider edge to fold over the blankets to keep them clean and to make it wear longer (narrow seams are not as durable). You can purchase sheets with wide decorative tops in order to make it easier to distinguish the sides for poor wee Leonard.