This is when a boy's sperm gets spurted out from the end of his penis. It usually happens at the time of orgasm when you have been sexually stimulated. It also can occur whilst you are asleep, when it is called a 'wet dream' or a 'nocturnal emission'.
When you ejaculate the two ducts which carry your sperm from your testes (balls) which are known as 'vas deferens' contract to propel sperm from the epididymis (which is part of your balls, where your sperm is stored). During ejaculation proper, your semen is ejected through your urethra which is the tube running the length of your penis, and the same one that you pee out of. Ejaculation is a reflex which cannot normally be stopped once it has begun without a great deal of effort (and sometimes pain).
The force your sperm spurts out during ejaculation varies greatly from one boy to another and from one time to another. The Americans, who have measured the speed of sperm during ejaculation say it is about 29 miles per hour! The normal amount of semen and sperm that comes out is somewhere between half a teaspoon full and a tablespoon full and depends on the amount of time that has passed since you ejaculated before.
How strongly your sperm shoots out each time varies greatly - some men can make their sperm shoot several feet whilst with others it just oozes out. Most boys need at least half an hour from ejaculating once to being able to do it again so don't worry if you can't come again straight away.
How long do you have to have sex before ejaculation happens?Again there are lots of differences between people as to variations as to how long you have to have sex before your ejaculation occurs. Some research has shown that most men can only avoid ejaculation during active thrusting for five minutes or less. A few can ejaculate more or less at will, and delay ejaculation for an hour or longer during sexual intercourse.
When a man ejaculates before he wants to it is called premature ejaculation. This can happen at any time and at any age but particularly when you first start having a sexual relationship with a new person and it can be really frustrating. To help it, you can try to take a deep breath, try squeezing the penis just below the tip or by thinking of something really boring like homework.