What is pre-cum?
The wetness that is produced in a penis in its excited state is called a pre-cum. It is also called pre-ejaculate because it comes before the ejaculate --- the other kind of wetness --- that comes from orgasming.
Pre-cum is a clear, alkaline fluid made up of enzymes and mucus that is released from the penis when it is erect due to sexual arousal. It comes out of the urethra, taking the same path that the ejaculate fluid takes.
This fluid is produced in the Cowper’s glands, two pea-sized glands located in the internal portion at the base of the penis and that have ducts emptying into the urethra. The quantity of pre-cum varies from person to person.
It can be easy-to-miss quantity for some while for others, it can be enough to soak their clothes or whatever (and whoever) is in the way. But it’s perfectly normal and there’s no way anyone can control the amount of pre-ejaculate they produce, nor can its timing be controlled; all automatic.
What’s the use of pre-cum?
Very simply, pre-cum really is a sign of how turned on you or your partner is. It’s nature’s way of honest communication, no shying away from saying there’s arousal. Pre-cum’s job description is more defined than this, though.
Now, remember where the pre-cum comes out of is also the path urine takes to come out, i.e. the urethra. Urine is acidic and the alkaline pre-cum neutralises that acidity so that when ejaculate comes, the sperm in it is not killed by the acidity in the urethra before it even goes out of the penis.
The body doesn’t know when it’s sex for pleasure and when it is to make a pregnancy. So, it always tries to keep the sperm fit for the latter situation. When doing unprotected intercourse inside a person’s vagina, the pre-cum also neutralises vagina’s acidity to keep a helpful environment for the sperm to swim up and collaborate with the egg to make a pregnancy.
Can pre-cum also cause pregnancy?
Even though pre-cum by itself contains no sperm, that is necessary to create a pregnancy, it can still cause a pregnancy. Here’s how. There can be leftover sperm in the urethra from a previous ejaculation. When the pre-cum fluid is on its way out of the penis via the urethra, it might also pick this leftover sperm on the way and carry it outside the penis. If there’s no condom on at the time, pre-cum upon entering a vagina can cause pregnancy.
There are other ways too. Some pre-cum might be on the fingers of either partner, and they may insert fingers in the vagina – straight entry for the sperm to create possibility of pregnancy.
Additionally, another scenario that’s a little unlikely but not impossible – the erect penis comes in contact with the vulva, close to the vaginal opening. Why it’s less likely to cause a pregnancy is because sperm can’t survive outside the body for long. But there’s still a tiny possibility, and when a pregnancy is not wanted, why leave any scope for it?