Bonobos use genital rubbing as grooming so its not really sex. The crazy thing about them is how closely they resemble Chimpanzees, until the 60's or 70's we thought they actually were chimps, but chimps are ridiculously violent and patriarchal, Bonobos are a complete 180 degree turn from that.

Not only do they use Gential rubbing(male on female, female on female, male on male, etc, etc) for grooming, but they also use it to settle disputes & greet new individuals. Haha wonderful thread.