Okay everyone, it's time to talk about female ejaculation - because it's not as mysterious as many would like to believe.

Scientists have found evidence that women who 'squirt' are expelling one of two different types of liquid - one pure urine, and the other a combination of urine and fluid from the female prostate gland.

Researchers in France back in 2015 were the first to observe the mysterious phenomenon using ultrasound scans, to discover that the ejaculate originates in a woman's bladder - and is made up mostly of urine.

The team, led by Samuel Salama, a gynaecologist at the Parly II private hospital in Le Chesnay, worked with a small sample of seven healthy women who reported "recurrent and massive fluid emission" when they were sexually stimulated. It's not uncommon for women to experience a little bit of milky white fluid leaking from their urethra at the point of climax, but the practice of 'squirting' enough liquid to fill a drinking glass is relatively rare.

"A few small studies have suggested the milky white fluid comes from Skene glands - tiny structures that drain into the urethra," wrote Helen Thomson for New Scientist at the time.

"Some in the medical community believe these glands are akin to the male prostate, although their size and shape differ greatly between women and their exact function is unknown."

Salma's team first asked the participants to submit a urine sample, and then their pelvis was scanned via an ultrasound machine to make sure there was nothing remaining in their bladders.

The women were left to either masturbate in the lab, or have sex with a partner, until they were just about to climax. This gave the researchers enough time to get their ultrasound machines at the ready.

In what must have been one of the most awkward moments of their lives, the women had scans performed on them as they were climaxing, and the expelled fluid was collected in sample bags. One last scan was taken of their pelvises afterwards to get a view of the bladder.

Oddly enough, even though the women had emptied their bladders before the big event, the scan taken just before they climaxed revealed that the bladders been completely refilled again, for no other reason than the women had been sexually stimulated.

The scan after the climax - and ejaculation - occurred showed that the volunteers' bladders were once again clear. The team published their results in The Journal of Sexual Medicine.

Soooo, does this mean the liquid that's being squirted during sex is urine? The team had already confirmed that it was coming from the bladder, so it's a good bet.

They compared the samples that had been bagged up during climax to the urine samples collected at the beginning of the study and found that in two of the seven women, the samples were both chemically identical.

In the remaining five women, the samples were slightly different.

The team found an enzyme called a prostatic-specific antigen (PSA) that was present in small amounts in these volunteers' ejaculated urine.

"PSA, produced in men by the prostate gland, is more commonly associated with male ejaculate," said Thomson at New Scientist, "where its presence helps sperm to swim. In females, says Salama, PSA is produced mainly by the Skene glands."

So when females ejaculate during an orgasm, they either release plain old urine, or urine that's been diluted by fluids from the female prostate gland.

Thomson spoke to an independent expert, Beverley Whipple, a neurophysiologist from Rutgers University in the US, who said that when we talk about female ejaculation, we should really only be referring to when PSA is released, not urine.

The remaining mysteries surrounding this phenomenon are whether or not it serves some kind of adaptive function, and why so few women are able to do it. Researchers think it could have to do with perhaps some women not producing PSA at all, or maybe the size and shape of an individual's prostate gland comes into play.

Salma thinks all women should be able to squirt "if their partner knows what they are doing", New Scientist reports.

