"Mating in Captivity" is a book by Esther Perel that explores the complexities of desire and intimacy in long-term relationships. Perel examines how the dynamics of love and eroticism can shift over time, often leading to challenges in maintaining passion. She emphasizes the importance of balancing the need for security with the desire for adventure and novelty. The book delves into the psychological aspects of relationships, discussing how external factors, such as societal expectations and personal experiences, influence sexual desire. Perel encourages couples to communicate openly about their needs and fantasies, fostering a deeper understanding of each other to enhance their connection.