The most common causes of semen in urine are an enlarged prostate, retrograde ejaculation, or if semen is left over in the urethra from previous intercourse or over masturbation habit. Generally, a man won’t notice if there is only a small amount of semen in the urine. Many men don’t discover that it is occurring until a doctor detects it during a physical exam. If semen is physically noticeable during urination, it will probably appear as a slight oozing directly before or after a man urinates.if this problem persists it makes physical and sexual weakness in future. The most common cause of semen in urine is when a man urinates shortly after ejaculation. There may be a trace amount of seminal fluid left inside or directly on the tip of the penis which mixes with urine as it exits. This is usually a very small amount and most men don’t notice when this occurs.Another possible cause of semen in urine is a swollen prostate. Since seminal fluids are created inside of the prostate gland, it is possible that some of it will leak or seep out at the time of urination. Other symptoms may also occur in men who have a swollen prostate, including urinary urgency and the inability to urinate entirely. Anyone who has these symptoms should consult a physician for a physical evaluation.. Semen leakage may occur directly before or directly after urination. Sometimes there will be semen noticeably floating in the urine afterward. Most of the time this is not cause for concern, but if other symptoms are present, a doctor should be consulted.. Some sexually transmitted diseases may cause unusual penile discharge which may look similar. In some cases, other symptoms will also occur.SO CONSULT A SEXOLOGIST DOCTOR for proper treatment.