nippledick
A slightly popular Japanese fetish. This involves the paraphilia of penises where the nipples on a woman's body (or possibly a man's) would occur. This is only illustrated in hentai, and probably the imaginations of kids that don't really understand sex too well.

(It is also present, but fiercely underrepresented, in America, but only in illustrated or furry porn.) 

This is commonly juxtaposed with futanari, hyperphallic, and sexual defecation, but very rarely used with lolicon.

An inexplicably common subfetish is shitting nipple dicks, in which shit comes out of the nippledicks.
So, you think you know all about Japan--do you know what nippledicks are?