The Sexual Double Standard (SDS) is an instrument used to judge sexual behavior, in which men are usually granted greater sexual freedom, while the same sexual behavior is condemned in women. Culture can be a relevant variable for the SDS. Therefore, we have examined the measurement invariance of the Sexual Double Standard Scale (SDSS) across the Spanish and Colombian populations, comparing this phenomenon by country and gender. The scale comprises two factors: sexual freedom and sexual shyness. The sample consisted of 1832 heterosexual adults (46.3% men, 53.7% women), 54.3% of whom were Spanish and 45.7% Colombian. Strong invariance was found. The reliability values were good for country and gender. Men and women from both countries supported greater freedom for themselves compared to the other gender. Furthermore, Spanish women, unlike their Colombian counterparts, supported greater sexual shyness for men. Thus, what some authors have labeled as a "reverse sexual double standard" seems to emerge.