Hmm...can't remember anything embarassing..must be some damn good firewalls in that there brain as I'm sure there have been many..but I do remember a stupid one.
My trick back in the day was putting ciggies (not mine, never smoked) out on my forearms (you know..being young stupid and 'ard and all that).
Sadly I decided to do this with a friends ciggie that he handn't finished so naturally he jumped up and went "oi I'm not done with that yet" , leant over and took a long hard drag on it to finish it...whilst it was pressed against my forearm.
when I removed it there was perfectly circular layer of bubbling fat which has left a nice scar to this day a decade later =p.
Luckily I was too drunk to feel it
And of course setting my own beard on fire with a flaming sambuka when my mate hit the punch line in a really good joke as I'm downing it, causing me to regurgitate a flaming pillar of sambuka onto my own face...