Fang Xudong argues that there are no successful arguments against same-sex marriage but that Confucianism does not prefer same-sex marriage. In particular, Fang objects to the slippery-slope argument against same-sex marriage, arguing that it is not successful. This commentary contends that the slippery-slope argument cannot be defeated based on the idea of equal marriage rights. I argue that Fang's reasoning for the Confucian preference to avoid same-sex marriage, based on the importance of natural conception and natural birth, is not valid. Furthermore, I argue that the idea of heterosexual union might not be essential for Confucian key doctrines.