He came back from business trip last week and I was just folding the clean washing. I came across a pair of underpants that aren't his - definitely not his. I know this as a fact. I looked in the label and they are from Debenhams and every other pair he owns are from M$S. So I jokingly say, you have someone else's underpants in your washing! cue, an awful lot of loud noise, trips upstairs to get the other 'matching' pairs for proof (from M$S so definitely NOT matching), asserting that they are definitely his, and I am wrong. Now what began as a fairly innocuous situation has developed into a scene where I am really wondering where these came from. My mind boggles at the possibilities - aibu to investigate further - and if not, then how do i investigate? Has anyone else had the same?