This question may be better for /r/askanthropology. Our closest relatives bonobos engage in similar activities.
"Bonobos eat a variety of foods, including fruits, nuts, seeds, sprouts, vegetation, and mushrooms. They eat various parts of plants, including the leaves, flowers, bark, stems, pith, and roots."
...
"Bonobo males tend to be a bit more polite. They ask first, by displaying themselves in a persuasive but non-aggressive manner, offering food or making other propositions-and bonobo females have the right to refuse. The sexual aspect of bonobo behavior is best understood in the context of bonobo culture. Sex does not necessarily mean the same thing to a bonobo that it does to a human. However, it raises compelling questions about the roots of human nature, and is particularly striking in contrast to chimpanzee society. Scholars continue to study this unique phenomenon and debate its implications."