Sexually transmitted infections, or STIs, have been and remain a shadowy but very important figure in human history. They played a role in World War II, in the development of the Internet, and in the show “The Bachelor.” Despite all their importance, for centuries they have been trying to push STIs out of the limelight, hushing up the difficulties associated with them. That's why we still know so little about them. And here comes Aina Park! For decades, she has been educating people about sexual health and equipping them with scientific knowledge to combat uncomfortable problems. And the truth is this: most of us are sexually active, but often completely unfamiliar with the universe of microscopic creatures that live under our blankets. And Aina Park intends to turn the tide and break the awkward silence that reigns around intimacy. Inside are frank answers to the questions hanging in the air from all curious adults. Aina Park, Ph.D. – Associate Professor, Department of Family and Community Medicine, School of Medicine, University of California, San Francisco; medical director of the California Center for Reproductive Health and medical consultant for the STI Prevention Division of the US Centers for Disease Control and Prevention.