It's the constant, eternal, invisible movement of life, and therefore of sex. Flowers doing everything they can to attract insects to their silky, juicy sex. Animals mating in puddles and in trees. The garden is nature's church where all orgiasts are welcome.
Guess it won't come as a surprise that I am fascinated by photos of people fooling around with cameras in private moments. I'm a voyeur by nature, and carefully-wrought images, however beautiful aesthetically, don't feed the pervy need to see people really naked, without artifice.
Ordinary bodies in natural poses are sexier to me than perfect specimens playing to cameras. I also love images of people at sexual play, whether it's SM/fetish stuff or just plain cracking themselves up (see above).
A reader (thanks, Six) once pointed out that I typically show people who look happy, and it's true. It's not only that I like to see people have a good time -- I think that people who are playful in bed are sexier. They get the point of sex: it's supposed to be a good time. If they aren't smiling, then I want to see them passionately engaged, so absorbed in the sex they barely look up at the camera.
Today is all about playful and spontaneous photos, including a sweet collection of explicit private swinger photos from the 1950s, a 1920s series on voyeurism, and some brave adult star wannabes from the 1990s.