I almost never cried until about 10 months ago, and then i started crying every time i saw something "cute", like puppies. Actually, these commercials about homeless animals used to make me positively bawl, and i've never been one to cry!
I've always been very strongly connected to my emotions; they rule my life, whether good or bad. Because of that, my submission is a very, very strong and compelling feeling, and when i'm with the right person, doing the right thing, it strikes me pretty deep. There was one person who knew me so well that he could tell when i needed to cry - he'd spank me just the right way, or whisper something in my ear, or even just give me a certain look, and the tears would start immediately. Like you, it wasn't a sad cry, it was an emotional release - literally, like there was too much pressure in the pipes and the valve had suddenly been turned to "full on". I said my emotions are very strong, but i am usually very composed, and i am really, really bad at saying what i need. I was just lucky enough that this person could tell immediately what i needed and how much.