А, и еще, если вы "не в России", то наверняка читаете английский? Вот,  результат исследования на эту тему: The present data based on ultrasonographic bladder monitoring and biochemical analyses indicate that squirting is essentially the involuntary emission of urine during sexual activity, although a marginal contribution of prostatic secretions to the emitted fluid often exists. Особенно обратите внимание на: squirting is essentially the involuntary emission of urine during sexual activity. И ссылка https://www.ncbi.nlm.nih.gov/pubmed/25545022