Caution: Link does contain suggestive material
When It Comes to Sex, Chimps Need Help, Too
"I couldn’t imagine how chimps managed this evolutionary leap. But then, I couldn’t imagine what they were actually doing. Using blades of grass to tickle one another? Building heart-shaped beds of moss? Using stones for massages, or vines for bondage, or — well, I really had no idea, so I called Dr. McGrew, who is a professor at the University of Cambridge.
The tool for sex, he explained, is a leaf. Ideally a dead leaf, because that makes the most noise when the chimp clips it with his hand or his mouth."
So, how is your self-esteem now? Apparently I don't know what I'm missing.