All research done on this has been anecdotal - interviews - with a few minor exceptions of sleep labs with observers. The results indicate that it is neither common nor uncommon. More women report awakening in a state of arousal than actually masturbating while asleep. Very few report experiencing orgasm while still sleeping, rather, they awaken and finish themselves (I do).
I represent a variation on this. I began seriously playing with myself during my first period. The irritation of the pad kept me in a state of arousal. My first orgasm came, unexpectedly, several months later - during my period. I began to fall asleep with a stuffed animal clamped between my thighs. To this day, nearly thirty years later, I am most comfortable sleeping with a firm pillow between my legs and this, no doubt, has generated some nocturnal activity; a form a masturbation.
Some of the modern sleep aids, as drug companies call them, do lead to various activities in sleep of which we are unconscious. These include eating, walking about, even drivving. I have seen no studies but cannot imagine that sex would be excluded - just not talked about. If you are taking some of this stuff, your masturbation could be a side effect. If you are not taking this, that would indicate that you probably have developed a behaviour not unlike my humping a stuffed animal when I was fourteen.
In either case, nothing to be embarassed about. Men commonly have oragasms during the night (though they usually awaken at the point of ejaculation); we women experience this less commonly and almost always awaken before orgasm. Blame it on the incubus who lives in your closet!
Brandye
Posted: 23 Sep 23:57