While love relationships between older men and younger (adult) women have been well-researched, the equivalent relationship of elder women with younger men has led a shadowy existence in research so far. At the same time, public interest in such relationships is growing, evidenced by interest in celebrity relationships such as those of Demi Moore, the 90 Day Fiancé reality TV star Jenny Slatten and her Indian partner Sumit, or the French President Macron and his wife Brigitte Macron, with a corresponding mainstream media. In public discussion, the older women in such relationships are often labeled as “cougars.” The slang term “cougar” is often used to label older females who seek a relationship (or relationships) with younger males (The Oxford British and World English Dictionary, 2012) and the younger men as “toyboys” or “cubs.” This chapter focuses on the impact that age difference has on relationships, the issues that arise for the partners, and which opinions and prejudices they have to face. In this chapter, relevant current research results are presented and discussed. In particular, possible significant factors such as gender and culture are considered in detail.