One of the easiest ways to know understanding about sexually transmitted disease is asking which form of birth control does the person uses. Using a condom is the best way to prevent nasty gonorrhea and more serious ones like herpes and HIV. However, condom alone is not effective. Many sexually transmitted infections can still be transmitted even if partners use condoms or other barrier devices. In the question, Jennie must know if her partner is having sex with others. If her partner does have other sex partners, Jennie is still facing higher risk of contracting infection.