The leakage of urine after the first coitus of a man may be caused by urethritis, prostatitis and other reasons. 1. Urethritis: It may be due to the lack of attention to sexual hygiene, or circumcision and vaginitis, etc., through sexual stimulation caused by men’s urethritis caused by frequent urination, urinary urgency, urine overflow at the mouth of the urethra and other symptoms. 2. Prostatitis: Sex can cause the prostate gland to become congested and swollen, and it is possible that the prostatitis caused by too much time spent in sex, cold and tired, will cause the abdomen to fall, frequent urination, urinary urgency, urinary incontinence, urine leakage, etc. The prostatitis can also be caused by the fact that the prostatitis can be used for the treatment of the prostate gland. To summarize, boys leakage of urine after the 1st coitus may have other reasons, need to go to the hospital in time to check, follow the doctor’s instructions for treatment.