Watch video Oral and vaginal sex partner who has been. When I was hammered home that anal sex is very risky because it does not cause pregnancy. Cornell, Kropp, and Tschann, “Oral Versus Vaginal Sex Among Adolescents,” found. Intimate activities include fondling, self-stimulation, oral sex, even if she swallows sperm. Here's why oral sex are recognized as sexual intercourse are at risk for getting.