I was staying at a holiday camp with my Christian youth group as we were attending a week long conference.
One night after being out late I hurriedly undressed and thought no more of it. In the morning I was late for a seminar and dressed as hurriedly as I had undressed the night before.
Everything was peachy until we were walking back to the chalet from the seminar and suddenly someone piped up "Ew, that's disgusting". Looking down at where they were pointing I noticed a pair of knickers lying on the floor.
"Oh yeah, that's gross!", I replied realising with mounting horror that they were mine.
In my haste to get undressed the night before I had left my knickers in the leg of my jeans and somehow without noticing on the way to my seminar they had slipped out. I must had a face like a beetroot but no one seemed to notice. For the rest of week I had to walk past my knickers every day as there was no way I'd dare claim possession of them! :)