balls an illustrated guide by BISH

Balls and Cum an Illustrated Guide

A guide to balls. How ejaculation works, testicular cancer, ball checks, prostate gland, G spot and ‘pre cum’

This guide can only really teach you some of the basics – you might want to have a look at your own private parts (in private) to see how all this feels for yourself.

***drawings of balls below***


Balls at rest and aroused

There’s a lot of variation in the size of testicles and balls. They also appear to change shape and size as the scotum reacts to pull them up into the body and to let them hang low again. There’s more on how this works below.

Balls when resting. They tend to hang a bit lower when not aroused. They all come in different shapes and sizes. One ball usually hangs lower than the other
Like penises, balls come in different shapes and sizes

When the penis is aroused this also has the effect of making the balls a bit tighter. It’s thought that this is to do with the cremaster muscle (see below).

Balls when aroused. Balls scrunch up a bit when the penis is aroused
Balls scrunch up a bit when the penis is aroused

Balls (also known as Testicles)

Testicles produce millions of sperm each day. Usually male bodies will have two of them. They get bigger during puberty (and the scrotum expands to allow for this) but if you have testicles they will already have dropped before puberty starts. A lot of people think that testicles suddenly ‘drop’ as a sign of puberty, but that isn’t true at all. They usually drop into the scrotum soon after birth.

Ask Bish When do balls drop?

It is normal for one to hang lower than the other (so they don’t bang into each other) and for one to be slightly bigger. They can swell up when sexually excited and can feel tender or a little bit sore – people call this blue balls (that’s also known as vasocongestion and it also happens to people with female bodies). This goes away after a while by itself. If you want to make that ache go away sooner you could masturbate. If that’s not your thing, maybe a cool bath or a shower might help.

Looking after them

They are delicate so look after them. Avoid tight pants and try and prevent them from getting hit playing sport or anything else. A number of things can go wrong with your balls. One of these is ball cancer which is very serious but also very rare. So get to know how your balls feel, so that you know if anything is unusual. They should be smooth and soft, like a hard boiled egg without the shell on, apart from the rear of each ball which will feel lumpy. Do this after a shower when your balls are hanging lower.

If you find any small lumps on your balls or if one of them has got noticeably bigger or heavier then GO STRAIGHT TO A DOCTOR OR CLINIC. Ball cancer is easily treated if caught early enough. Most of the time it isn’t cancer, just a harmless cyst. For more about this go here


The muscles inside the scrotum protects the testicles also and controls their temperature by raising them up and down. If it’s warm they hang down, if it’s cold they tighten up. This is because sperm needs to be slightly cooler (2 ° C) than body temperature.

Inside the scrotum

The muscles raise the testicles up into an area called the inguinal canal. Sometimes the testicles can actually pop all the way into the body. This can happen if you get suddenly frightened by something, if you laugh really hard, or you get the shock of being really really cold (like if you jump into a cold lake). If it does happen it’s chill. Read more about the balls going up inside the body.


People produce around 1 or 2 teaspoons of cum – it ejaculates at up to 40 kph (breaking the speed limit). Around 99% of ‘cum’ is semen which helps to provide energy, and assistance for the sperm in order to fertilize an egg. It’s mostly water. Some cum is thick and sticky, some milky and some very watery. It can vary a lot. Semen’s job is to help sperm to swim but it also keeps them alive with minerals.


Sperm is created and stored in the testicles. Even though only 1% of semen is sperm there can be up to 150 million in each ‘load’ of ‘cum.’ Their role is to fertilise eggs in order to begin a pregnancy.


Some people find they have a little bit of fluid at the tip of their penis before they ejaculate. This ‘pre-cum’ is not actually ‘cum’ but a fluid which cleans the urethra.

Is there sperm in pre-cum?

This study suggests that some people do have sperm in their pre-cum and some people don’t. Where there is sperm in pre-cum in a minority of cases it is mobile enough to be fertile but there are much less of them than in a normal ejaculation.

If a penis was to pre-cum inside someone’s vagina there would be a risk of pregnancy, but this would be a lot less than if someone fully ejaculated inside a vagina. One of the tricky things about pre-cum is that people often don’t really know when they have fully ejaculated or not. I wrote a piece about the chances of pregnancy from having sex just once, I bet you guess wrong.

People more likely to get and give an infection from pre-cum or unusual discharge (if either partner has an infection), which is why it’s important to put a condom on before the penis enters someone.

Ejaculation – what happens?

Ejaculation: what happens?

Sperm starts it’s journey in the testicles. It then moves to the epididymis, which swells a bit before ejaculation. Then the sperm travels up the sperm tubes (called the vas deferens for you sex geeks) and then up to to the prostate. The prostate is where semen is created and here they both get mixed up. Then during ejaculation muscles around the prostate pump the semen and sperm out of the erect penis at high speed.

The refractory period

After ejaculation penises can’t usually get hard again for a few minutes (10 – 30 minutes, sometimes sooner, sometimes longer). This is called the refractory period and is totally normal, it’s also normal to not have a refractory period. For a lot of people this means that after ejaculation they aren’t really interested in sex for a while. However,  if you do feel like you would like to continue having sex, you could — you don’t need an erection to have sex. I’ve got more advice about that here. Here’s more about ‘the hard on’.

Please leave a (nice) comment below if you like or ask me a question here.

© Justin Hancock, 2024 Find out more about me and BISH here.

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I’ve been a sex and relationships educator since 1999 (with a background in youth and community work). In that time I’ve taught and given advice about sex and relationships with thousands of young people in person and millions online. I’ve worked with many charities, local governments, schools and youth organisations facilitating training and workshops. My two books, Enjoy Sex (How, When, and If You Want To) and Can We Talk About Consent? are widely available around the world. I’ve been on the telly and the radio and have written articles for newspapers and magazines. I’m also a member of the World Association for Sexual Health. Read more about me and BISH here. Find out about my other work here Justin Hancock

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46 thoughts on “Balls and Cum an Illustrated Guide

  1. Even as a 42 Female, this posting taught me a lot! 👍🏻👍🏻 I always wondered what I had missed when I got kicked out of Sex Ed! 🤔 but for real, this was well written and very informative! Good job 👏🏻

  2. Hello everyone, 15 year old boy here. I ‘m a little worried about my right testicle as i have been feeling a bit of pain since the night between thursday the 26th and friday the 27th of january. It’s only when i slightly touch it with a finger or when i accidentally hit it with my leg. Please help.

    1. That’s a good question. It’s not going to feel the same for everyone and some people might start to cum before they realise. If you masturbate, you could just try to pay attention to what happens if you make yourself cum. It’s all about the muscles contracting around the prostate gland pumping the sperm and semen out. Some people know when this is about to happen, or when the muscles start to contract. But I think it’s a practice thing.

    1. Hi Buster Gonad. I don’t think that there’s any way for you to increase the amount of semen you produce. Even though you may have unfeasibly large testicles that doesn’t really make a difference to the amount of semen you cum. Semen is made and stored in the prostate, not the balls. Some people say that if you drink more water then you might make more semen (as semen is mostly water, sound legit), so perhaps try it and see? If you and your GF wanted to glaze her like a Krispy Kreme you could also use other substances that look a bit like semen (which often happens in porn shoots). Good luck with it. Justin

  3. My penis is quite large, but my testicles are small and lopsided. Wouldn’t the fact that I have a large penis mean that I produce a lot of testosorine and wouldn’t it be more likely to have a matching set of balls to a big cock?

    1. When pleasuring hold the penis up high and quickly cum when ready. Do it slow then fast at the end. Good luck.Gerry

    1. It can be a good idea – particularly if you have a vagina as it can prevent some infections in the pee hole (urethra).

  4. I find it disappointing that you seek perfection in terminology for the female explainations, but then you propogate the slang term “cum” rather than using proper terms.

    1. Fair point. I guess I’m trying to have a mix of using proper terms and terms people understand immediately. For example ‘ejaculate’ (which would be the correct term) is both a verb and a noun.

  5. I have same problem my right testis is bigger then left and I have no pain in it every thing is normal should I can pragnent girl I need answer beacause I am worried alot

    1. Often/usually one testicle is bigger than the other, so that is totally fine. No need to worry. The only time to worry is if your testicle has changed in size recently, which could be a sign of a problem.

  6. Good and valuable information given very simply and effectively with that good ol’ British wit/humor applied. Good job!

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