Don't want to offend anyone, but I had a girlfriend that was prone to yeast infections, turns out her boyfriend was passing it to her. See he had an overgrowth of yeast in his body, especially in his mouth. I think that is called thrush. Anyway, you can imagine how he was passing it back to her. She had to refrain from that particular activity. Poor Girl!!!
I forgot... Douching is not good. It washes out all of the good bacteria. Also makes you prone to all sorts of infections.