OBJECTIVE: It seems that traditional gender norms influence young women's and men's sexuality differently. However, little attention has been paid to ideal images of sexual situations. This study identifies young heterosexual men's ideal images of sexual situations and their expectations of themselves in sexual situations. STUDY DESIGN: The present study employs a qualitative design. Twelve Swedish men (aged 16-20) participated in individual in-depth qualitative interviews. The interviews were transcribed verbatim and analysed using the constant comparative method from grounded theory. RESULTS: Our study revealed that the young men's conceptions of normal sexual situations were divided into two parts: sexual situations in relationships, and sexual situations in one-night stands. Their ideal image, "a balanced state of emotional and physical pleasure", was influenced by the presence/absence of intimacy, the partner's response, and their own performance. The greatest opportunities to experience intimacy and the partner's response were found during sexual situations in relationships. In one-night stands, the men wanted to make a good impression by performing well, and behaved according to masculine stereotypes. CONCLUSION: Stereotyped masculinity norms regulate young heterosexual men's sexuality, particularly in one-night stands. Sexual health promotion should emphasize the presence of these masculinity norms, which probably involve costs in relation to young men's sexual wellbeing.