During the course of the study, participants will evaluate 3 products: 2 distinct suppository formulations and 1 gel formulation that represent a range of rheological and other biophysical properties of potential microbicides being designed for rectal/dual compartment use. Participants will evaluate the experience of suppository use (as compared to gel use) in the context of receptive anal intercourse (RAI) among males and females, and in the context of vaginal intercourse (VI) (females). Each participant will be randomly assigned to the order in which they will evaluate the 3 products. Participants will be required to complete a brief phone survey (<3 minutes) every day, beginning the day after they start their first product evaluation period and continuing until they complete their final study visit (approximately 10-20 weeks). The phone survey includes a short set of questions about sexual behavior and product use during the time since the last phone survey (about 24 hours). After a sexual encounter that includes RAI/VI and study product use, participants will be required to complete a web survey about their experience with the study product. After a participant has evaluated all three products, participants complete an individual in-depth interview with study staff about their experiences with the study products.