Systematic research on sexual development in adolescents with autism spectrum disorder (ASD) remains scant, notwithstanding the often-suggested relation between ASD, atypical, and even sexually offensive behaviours. This study compared follow-up data related to lifetime sexual experience (LTSE) in a homogeneous group of adolescent boys with ASD (n = 30), aged 16–20, with a matched group of boys in the general population (n = 60). Most boys in the ASD and control groups reported masturbation and having experienced an orgasm. The proportion of boys with ASD that had no partnered sexual experience was larger than in the control group. This difference was mostly explained by significantly fewer boys with ASD, compared with controls, who reported experience with kissing and petting; no significant differences emerged relating to more intimate partnered sexual experiences. The results suggest the existence of a subgroup of boys who have not (yet) entered the arena of partnered sexual experiences—a finding in line with research in adult samples. There were no differences relating to sexual abuse or coercion. Exploration of the partnered experiences revealed a variety of types of partners, mostly of comparable age. Several boys with ASD had not anticipated their sexual debut. Although they felt ready for it, some boys reported regret afterward. The hypothesised sexual developmental trajectories are subject to further research, but the sexual experience in this sample and the assumed developmental differences indicate the need for early, attuned, and comprehensive sexuality-related education and communication.