I’m not asking this out of prurient interest, as lame as that may sound. I’m curious about the physiology involved with the small percentage of women who experience ejaculation of fluid during orgasm. I won’t go into it, but I have personal knowledge that the fluid is not urine or a lubricating secretion. What exactly is the fluid, and from what part of the female anatomy does it emanate? –Bill B.

80 percent stick their fingers in their ears and sing, “OH BEAUTIFUL FOR SPACIOUS SKIES, FOR AMBER WAVES OF GRAIN….”

Best of Chicago voting is live now. Vote for your favorites »

First let’s agree on what we don’t know. I don’t want to get into the details either, but I too have personal knowledge of the fluid under discussion. I agree it’s not a “lubricating secretion”–unlike the vaginal fluid produced during arousal, the ejaculate is watery and somewhat acrid to the taste. But I can’t say definitely that it’s not urine, at least in part. Unless you’ve got an unusually refined palate, Bill old buddy, you can’t say it’s not either without access to a lab. For years the standard explanation was that the stuff was urine squeezed out of the bladder or urethra during the state of heightened muscle tension that accompanies orgasm. But conventional wisdom has shifted over the past two decades, and most sex therapists now seem to think the discharge is more than plain old stress incontinence. Little research has been done, however, and none of it’s conclusive.

Both these assumptions are questionable. According to Milan Zaviacic, a leading authority on the female prostate, in only 10 percent of women is the gland located at the site commonly believed to be the G-spot. Even in cases where the female prostate and the G-spot coincide, no one has persuasively shown how this would account for the intense sensations associated with the G-spot: the gland doesn’t seem to be supplied with a cluster of nerve endings, for instance. (The outer third of the vaginal canal does have plenty of nerve endings, but as far as we know they’re not concentrated at a particular location.)