According to the United Nations Convention on the Rights of Persons with Disabilities, people with intellectual and developmental disability (IDD) have the right to live out their gender/sexuality according to their needs and wishes. However, romantic relationships and sexuality in people with IDD are still taboo in some societies. However, what is currently known about the extent to which people with IDD can exercise these rights and where problems may arise? This chapter first defines the term IDD and then uses the concept Scheme of Emotional Development (SEO or SEED concept) to emphasize the importance of the socioemotional developmental level of a person with IDD, particularly in assessing their understanding of romantic relationships and sexuality. It describes the role that romantic relationships and sexuality play for people with IDD and where people with IDD due to their “being different,” but especially due to their specific spatial and social environment, have problems implementing these in everyday life. Of particular importance here is the living environment (e.g., living in a residential facility for people with IDD) but also the role of professional caregivers, relatives, roommates/colleagues, society, and the media. The statements in this text show that people with IDD can only live their romantic relationships and their sexuality according to their needs and desires if caregivers, relatives, and other people who deal with them professionally and privately have sufficient knowledge about the socioemotional development level of these persons.