I can't really think of anything embarrassing, but I've done a vast array of really silly or stupid things, the majority of which involved lots of drinking before or during.
Lessee... turning down a beauty pageant contestant's invitation to sleep with her because I was afraid I'd miss something fun at the party. I was shunned by my friends for days and she told folks I was gay (I wasn't then or am now, heh).
Passed out on a golf course and woke up with snow falling on me.
At a party, a guy was asking about one of the girls he'd met that night. The music was loud, people were laughing and talking, so I was shouting to be heard above the din. Evidently I shouted, "And she's got HUGE t****!" while sitting right next to her. I had no idea she was there.
No...nothing to be embarrassed about that I can recall. I really regret little in my silly and checkered past. Just goofy stuff.