My day is complete. I just read this in Dan Savage's column this morning:
Q. You probably get this question every day. I'm a man who loves it when my girlfriend fucks me with a strap-on. Another great thing: My girlfriend ejaculates frequently and plentifully when we have sex, and she has done so when she's pegging me. Which leads to my question: What are the possible issues from getting female ejaculate in your ass? I am thinking about modifying a toy in a way that might enable her to squirt up my ass. It probably won't work, but I am going to try. Because if it does work...
Oh My Fucking God
A. I get questions about female ejaculation every day—where does that shit come from? How the hell can I/my girlfriend learn to do that shit? Is that shit really piss?—but you're the first person to ask me about modifying a sex toy so as to enable a woman to come in a man's ass. (You're going to want to patent that thing if it works, OMFG.)
Allow me to quickly dispense with the usual questions: It comes shooting out of a woman's urethra; practice, practice, practice; that shit isn't piss. How do we know it's not piss? Science!
In 2007, a crack team of sex researchers in Vienna "collected" lady ejaculate from two lady ejaculators—not a huge sample, admittedly, but two lady ejaculators are better then none—and rushed their lady ejaculate to the lab, where it was "evaluated biochemically." They published the results of their study in the Journal of Sexual Medicine ("The Female Prostate Revisited: Perineal Ultrasound and Biochemical Studies of Female Ejaculate," JSM, September 2007). They concluded that lady ejaculate isn't piss, it's come: "The fluid emitted [was] clearly different than urine voided prior to sexual activity," they wrote. "The values show that the source of fluid expulsion during orgasm is not urine, but is rather similar to male ejaculate."
As lady ejaculate is chemically similar to gentleman ejaculate, OMFG, the risks of a lady ejaculating in your ass would presumably be similar to the risks of a gentleman ejaculating in your ass: You would be at risk of acquiring any sexually transmitted infection she might have. But if your lady ejaculator is disease-free, OMFG, then letting her come in your ass is a risk-free, if not squick-free, activity.