This is actually very educational. It shows how the perineum muscles pump and contract during a man's ejaculation. At the same time, it is very arousing to watch, and gets me very horny. This could be because I'm a bisexual male? What can I say, I'm turned on and fascinated about the male sexual anatomy, especially in this position as seen in this video. Everyday, I'm getting more gay, and I love it.