Lan Zhanfei said he was forced to give a semen sample as a form of threat—biological evidence to prevent him from calling the police. Many people online don’t believe this, claiming he must have been caught in a honey trap while fooling around, or saying there’s no way someone could be forcibly made to ejaculate, and that he’s just making up a story…

But from a physiological perspective, forced ejaculation is absolutely possible. The neural centers controlling ejaculation in human males are actually low-level neural centers located in the spinal cord. There are two centers: the “emission center” and the “ejaculation center.”

The emission center is located in the thoracolumbar segment (T12-L2) of the spinal cord's sympathetic preganglionic neurons. It controls the process of moving semen from the epididymis, vas deferens, prostate, and seminal vesicles into the prostatic urethra—think of it as “chambering a round.”

During the erection phase, our parasympathetic nerves (sacral spinal cord S2-S4) mediate dilation of penile blood vessels and engorgement of the erectile tissue. When sexual stimulation accumulates to a critical point (ejaculatory threshold), the emission center (T12-L2) is strongly activated by the sympathetic nerves. Once the posterior urethra is filled with semen, the local sensation of fullness stimulates the spinal ejaculation center (S2-S4) to trigger release.

In simple terms, throughout the entire process—arousal (erection), preparation (emission), and release (ejaculation)—our cerebral cortex does not need to be involved at all.

Psychological activities like sexual fantasies and visual stimulation originate in the cerebral cortex and can trigger sexual arousal, which is then transmitted down to the spinal cord. These can serve as “triggers” for the process, but they are not strictly necessary…

Even if someone is bound, restrained, and threatened, their eyes could be covered and their genitals stimulated locally to eventually cause ejaculation. Emotions such as anger, fear, discomfort, and sadness, which occur in the cerebral cortex, theoretically do not have to affect the ejaculation process.

There have been medical cases of patients with high-level spinal cord injuries above the ejaculation center (e.g., cervical spinal cord injury), where the brain’s control over the spinal cord is severed but the spinal reflex arc remains intact. Through reflexive stimulation (such as penile vibration or rectal electrostimulation), ejaculation can be induced bypassing the brain and directly activating the lumbar-sacral spinal cord ejaculation center—this is called “reflexive ejaculation.” The patient does not experience subjective orgasm.

So when a victim says they were forcibly made to ejaculate, it is entirely possible. The semen collected is not necessarily evidence that he was fooling around and got caught in a honey trap…

This kind of forced semen extraction is not only unlikely to induce orgasm but is also highly likely to cause severe psychological trauma and even sexual dysfunction! Because under such circumstances, being forcibly made to ejaculate could cause the victim to recall this painful memory whenever ejaculation is about to occur. To avoid this painful arousal, the brain may start to block top-down sexual excitement, potentially leading to secondary erectile dysfunction or even infertility.

Criminals collect victims’ semen mainly so that if their crime is exposed, they can plant the evidence on a woman and frame the victim for rape… As a doctor, when I read about this detail, what I felt was not curiosity, but an intense sense of disgust at this criminal method… Such a despicable tactic could not have been thought up in a day or two. It must have involved meticulous planning and long-term rehearsal.