File:Adult male masturbating then ejaculating.webm

English: The video on the left side shows a male masturbating for approximately 90 seconds while sitting down in a chair, then ejaculating. The video on the right has been slowed down and starts at the moment an orgasm has been achieved, then continues until the end of the ejaculation process. The two videos have been synchronized to end at the same moment in time.

The purpose of the split screen video is to show the appearance of the penis and scrotum, pre and post ejaculation side-by-side. Notice the scrotum is loose while masturbating, then it contracts and pulls the testicles up while ejaculating.

During ejaculation, a total of 14 muscle contractions can be seen by observing the bottom left side of the scrotum as it pulsates towards the inner thigh. The first muscle contraction produces no semen. The second contraction causes a small amount of semen is expelled, followed by a larger amount during the third contraction and fourth contraction. The video ends after all visible semen has been expelled. Approximately 14 days had elapsed since the last ejaculation before this video was recorded.