Re: my son came home in someone elses underwear
DD did this once. She came home in a pair of too large little mermaid panties, and I knew the instant that I saw them they weren't hers. I don't buy character panties for her. She'd had an accident at school and the teacher had some extra sets of clothes just in case the child didn't have one with them. So perhaps that's what happened to your DS? Would reduce the squick factor since if they were a spare set that the teacher provided, they'd be clean.