From kissing to coitus? Sex-of-partner differences in the sexual milestone achievement of young men.

Scientific information regarding normative patterns of young men's sexual behavior is insufficient, especially regarding the impact of sex of partner. We explored the age at which 255 young adult men achieved several milestones (e.g., first kiss, manual-genital contact, intercourse) as well as the sequence of milestone achievement and stability in sex-of-partner preferences as a function of sex-of-partner experiences. Mean ages of milestone achievement were consistent with the extant empirical literature. Men with only female partners were younger at first kiss and first relationship, and older at first intercourse than men with only male partners; they also reported an almost universal sequence of milestone achievement and little change in sex-of-partner preferences. Most men with male partners reported increased preference for male partners over time. Men with partners of both sexes tended to demonstrate patterns consistent with the relevant sex-of-partner group. Findings suggested a common male sexual trajectory and sex-of-partner dependent trajectories.