Another cause of vaginosis is sleeping around with men who don’t use condoms. Even a single shot of semen will temporarily disturb the ecosystem of the vagina. Sperm can’t swim in the biting climate of a healthy vagina, so they’re buffered in a solution of acid’s biochemical yang, alkaline. Semen is highly alkaline, with a pH of 8. It is more alkaline than any other body fluid, including blood, sweat, spit, and tears. For several hours after intercourse, the overall pH of the vagina rises, momentarily giving unsavory bacteria the edge