Research has shown that individuals in romantic relationships often avoid discussing past sexual experiences. To ascertain whether past relationships and past sexual experiences were considered to be "taboo," 102 individuals involved in romantic relationships were asked to list the topics that they were reluctant to discuss with their partners. As past relationships and past sexual experiences were reported as topics often avoided, responses to an open-ended questionnaire were coded to determine: (a) the reasons individuals give for avoiding talk about past sexual experiences and (b) whether there are sex differences in how often those reasons appeared in responses. In descending order of prevalence, respondents reported that they tend to avoid discussing past sexual experiences due to four main concerns: (a) belief that the past should be kept in the past, (b) identity issues, (c) perceived threats to their relationships, and (d) emotionally upsetting feelings. Men and women displayed extreme similarity in the frequency with which they indicated particular reasons for avoidance. Data-inspired suggestions for individuals hoping to elicit discussion of past sexual experiences with partners are offered.