Elacatinus oceanops and Elacatinus evelinae are two species of tropical gobies, found in the Caribbean Sea, that play an important role in the coral reef ecosystem. In fact, they are key players in cleaning mutualisms - cooperative interactions between cleaner organisms that remove ectoparasites from the body of their “clients”. Cleaners usually are restricted to a small home range known as “cleaning stations” where they advertise their service to potential partners. Moreover, cleaner gobies are known for their monogamous behavior, in which pairs remain closely associated during both reproductive and non-reproductive periods. Their courtship behavior is characterized by side by side quivering motions, contact and territorial defense, to which both of the partners contribute. Until now, the potential of climate change on the mating behavior of these cleaner fish is unknown. Here we demonstrate that the chronic conditions of ocean acidification (delta pH 0.4; pH 7.6) and warming (+4 °C above ambient temperature; 30 °C) predicted to the end of the century impaired courtship behavior, and consequently elicit deleterious effects reproductive capacity. The cascading impacts of such findings on the future resilience of coral reef ecosystems are also discussed.