Why can masturbation lead to ejaculation while sex sometimes doesn't?

Patient's question:

First additional question: That doesn't mean there's a problem with the body, right?

Doctor's answer:

1. Factors related to mental and psychological aspects
2. There may be a condition of excessive prepuce
3. Low sensitivity of the penis skin. It is recommended to go to a formal specialized hospital for examination to avoid the dissatisfaction between couples due to the inability to ejaculate, which also harms the health of the male himself and may be a factor in male infertility! Therefore, patients with anejaculation should seek treatment from experts in the hospital as early as possible.