Chimpanzees have been observed kissing, raising questions about whether humans and chimpanzees are the only apes or animals that engage in this behavior. The discussion explores the evolutionary and cultural aspects of kissing, suggesting that it is primarily a cultural practice linked to physical intimacy and attraction. Kissing serves as a proxy for mating, especially during prolonged courtship periods, particularly in adolescence. Different cultures have alternative rituals, such as nose rubbing, indicating that kissing is not universal. The conversation highlights two dimensions of kissing: non-sexual, as a sign of affection and intimacy, and sexual, which enhances arousal and prepares partners for sexual activity. The origins of kissing are traced back to European customs, with some studies suggesting that it evolved from maternal kisses, which may have had health benefits for infants. Overall, kissing is portrayed as a complex behavior with both emotional and biological significance.