I remember I had consumed about 3 litres of Pepsi one day and the teacher wouldn't let me go to the bathroom. When we were heading home I ran to the end of the platform at a train station (we were waiting for a train obviously) and p*ssed into a large bush there. I must have been going for 2 whole minutes or more. Trouble was the the leaves in this bush were large and so all the urine was moving back along an intricate pathway of leaves and falling onto my shoes and lower leg. It took me a good minute to realise. That was pretty humiliating.
In second or third grade, I got confused about the date of my school's Halloween party, and I walked there wearing my costume a day early. Moreover, my costume, homemade by my mom, consisted in part of bright red swimsuit briefs over white long johns (she thought I was a weightlifter, carrying a pair of doorknobs attached end to end like barbells, but I thought I was superman), and the other kids made fun of me for coming to school in my underwear.
Probably walking in on my boyfriend's step dad taking a leak and then having just arrived at their house, I said "hi" and quickly walked away.
Most embarrassing was when I was at a party and I started making out with this guy and I didnt realise that it wasnt my boyfriend
There's so many, I can't single out just one....Keep in mind I'm 60 and still working on which one it is...LOL
When I was running on the beach and my bikini top broke and fell off.
Its so embarrassing, that I don't want to remember anymore!
Or yet to be...:)