Why does sex not lead to ejaculation?

Patient's question:

How to have sex without ejaculation has 3 time months

Doctor's answer:

Ejaculation failure refers to a situation where the penis is erect during masturbation, but no semen is released after masturbation. There are three different types of ejaculation failure:
① During sexual activity, the male does not experience sexual desire climax, nor does he perform the ejaculation action or release semen. This is due to dysfunction of the cerebral cortex and endocrine imbalance, leading to excessive inhibition of the lower sexual center.
② During sexual activity, the male experiences sexual desire climax, but does not perform the ejaculation action or release semen. This is due to the weakening of the function of the sacral spinal cord ejaculation center.
③ Retrograde ejaculation: The male experiences sexual desire climax and performs the ejaculation action, but no semen is released. This is caused by the lack of coordination in the function of the ejaculation center.