No, humans are not the only species that mate facing each other. While the majority of animal species engage in mating with the male mounting the female from behind (referred to as "dorsal-ventral" copulation), there are some exceptions in the animal kingdom where mating occurs in a face-to-face position.
One well-known example of face-to-face mating is found in bonobos (Pan paniscus), which are close relatives of chimpanzees. Bonobos are one of the few species, besides humans, that regularly mate in a ventral-ventral position, meaning the males and females face each other during copulation.
In addition to bonobos, some other primate species have been observed engaging in face-to-face mating to varying degrees. This includes certain species of gibbons (small apes), orangutans, and even some types of macaques.
It's important to note that the mating behavior of animals is incredibly diverse and can vary significantly between species. The reasons behind particular mating positions or behaviors are often influenced by factors such as social structure, mating strategies, and anatomical adaptations. The face-to-face mating position observed in certain species may be associated with specific social behaviors, the establishment of social bonds, or the dynamics of dominance and cooperation within their groups.
While face-to-face mating is relatively rare in the animal kingdom, it does occur in a few species besides humans, providing intriguing insights into the diversity of reproductive strategies across the animal world.