Like got4boyz, I can't claim a real "embarrasing" moment -- yet. But I know, my turn will come. I've helped a few newbies out of potentially - well red faces - in fact just last Saturday. The very last o/w (confined of course), one of the students is getting his gear together, when I heard the cry of "oh no" then *!&@*!&@. I hurried over, figuring equipment failure, but no. Much to my relief it was a case of "I forgot my swimsuit". You have to remember that it's the dead of winter here, so any of his street clothes were not appropriate as a temp solution. Fortunately for him, I had been trying on a dry suit earlier, and had brought my skin to help out the fitting. We all had a giggle, although the main colour is black, the accent is sort of a zebra stripe. We called him "Tarzen" for the class.
Some of the tales here have kept me laughing!