Sexuality has been censored by Spanish culture, where legal progress in the form of new policies about sexual diversity rights has not been followed by lower levels of social discrimination. This has affected sexual development across the lifespan for both sexual minorities and heterosexual people who experience their sexuality outside of heteronormativity. However, the literature has regularly excluded the possible consequences of the experience of sexuality within prescriptive categories, particularly in heterosexual people. This study delves deeper into the same-sex experiences of heterosexual women and men and the discomfort they may feel toward such experiences in Spain. A total of 2900 young Spanish people who self-identified as heterosexual completed a questionnaire on sexual diversity and experiences related to sexual orientation. The mean age was 24.22 years (SD = 5.71), 71.1% were women, and 28.9% were men. More heterosexual women than heterosexual men reported having had same-sex attraction, fantasies, desires, and behavioral intentions. However, these men and women reported having similar levels of same-sex sexual intercourse. The discomfort level experienced was higher among heterosexual men and younger people, suggesting the possibility that traditional norms restrict behavioral expression of sexuality among these individuals. At least in the Spanish context, these gender differences should be taken into account to adjust all psychological and educational interventions in the future to improve inclusive sexual attitudes and the treatment of discomfort with sexual orientation. Following these results, research on sexual diversity should focus on young heterosexual people who have different same-sex experiences according to gender differences.