This study builds on existing research into how young people's emergent sexual development is connected to parent-child sex-related communication through avoidance vs. disclosure. Over the course of one year, a total of 21 young people (age range 12-17.5) reported in longitudinal qualitative diaries their (1) everyday sexual experiences and (2) sex-related conversations with their parents. Using a mixed-methods approach, findings show that less sexually experienced participants reported greater avoidance of parent-child sex-related conversations than more experienced participants. The sex-related conversations of more experienced participants mainly concerned overt experiences in the form of everyday issues with their romantic partner, while the conversations of less experienced participants were characterised by more covert experiences such as opinions about romantic relationships in general. These results suggest that the degree to which young people feel comfortable talking about sexuality with their parents partly depends on when the conversation takes place during a young person's romantic and sexual development.