Sexual organ

Are the buttocks a sexual organ, as the FCC asserted? Many argue it is in fact not an organ, but...

From dictionary.com:

or·gan /ˈɔrgən/ Pronunciation[awr-guhn] –noun 1. a musical instrument consisting of one or more sets of pipes sounded by means of compressed air, played by means of one or more keyboards, and capable of producing a wide range of musical effects.

I don't know about keyboards, but the "compressed air ... producing a wide range of musical effects" part seems to match well.