Lips

A primer on kissing (tip of the hat to Andrew Sullivan):

A passionate kiss causes our blood vessels to dilate as the brain receives more oxygen than normal. Our cheeks flush, our pulse quickens, and breathing becomes irregular and deepens. Our pupils dilate, which may be the reason so many of us close our eyes. We also activate five of our twelve cranial nerves that spread out intricately to different parts of the face. The nerve pathways guide the way we interpret the world by helping us see, smell, hear, taste, and touch.

On top of that, our lips are associated with a disproportionately large part of the brain. Sex researcher Alfred Kinsey even reported that some women could reach orgasm from prolonged deep kissing without genital contact. While this sounds unusual, it likely has to do with the way our lips are packed with sensitive nerve endings so that even the slightest brush sends a cascade of information to our brains that often feels very good. Although we often don’t think of them in this way, our lips are the body’s most exposed erogenous zone.

The kiss is a universal language that transcends time and boundaries. Decades ago, anthropologists estimated that over 90 percent of cultures practiced the custom, and with the rise of the Internet and ease of travel in the 21st century, it’s fair to assume that nearly all of us are doing it.

I think I've been turned on.