Haha, I'm looking for yaoi in which the seme or uke (preferably the seme) has a tongue ring! It's my new obsession. Some thing like in the 7th chapter (Love Lock) in Kedamono Nanbiki?

In Bondz by Kawai Touko and the fourth story in Pet of Love by Sakura Haiji the ukes get their tongue pierced, but they get them towards the end of the story and neither are used. In Bondz, it is essential to the story.