There are several reasons for premature ejaculation at the age of 16: 1. Excessive semen accumulation, the accumulation of a large amount of semen in the reproductive organs will produce a feeling of fullness, and there will be seminal emission when there is no sex, and easy ejaculation when there is sexual contact with the vagina. 2. Excessive masturbation, excessive masturbation will cause a large loss of hormones in the body, and will also bring damage to the nervous system of the reproductive organs, which will then lead to premature ejaculation. 3. The sexual excitement of teenagers is particularly high, and with a little stimulation, the penis will become erect and may ejaculate upon contact with the female vagina, resulting in premature ejaculation.4. Insufficient sexual experience and excessive mental tension, if there is insufficient sexual experience, excessive mental tension, and usually no excessive masturbation or seminal emission, the amount of semen will increase a lot more than usual before the start of sexual life, and during sex Then the phenomenon of premature ejaculation will occur.