Q: To perform anal sex on a person, a lubricant is needed. Would semen work?
Dr. Klein: Unless a man’s sexual health is perfect, his semen can carry viruses and other things someone might not want in their anus. Assuming the man is healthy, semen is a perfectly good lubricant — but the average man does not ejaculate nearly enough to make anal sex comfortable. Remember that it will be absorbed into the skin after just a few minutes, and more will be needed; I don’t think anyone would enjoy that kind of performance pressure to create more.