create implication nipple_rings -> nipple_piercing
create implication clitoris_ring -> clitoris_piercing
create alias nipple_sleeve -> nipple_sleeves
In the past I argued for not implicating the rings to piercings for the handful of examples where they fit around the nipple/clitoris like a ring on a finger, but after seeing post #1873683 I changed my mind. They're distinct concept to try and force into a single tag, and the rings are overwhelmingly piercings anyway and treated as such.
I've replaced nipple_rings and clitoris_ring with nipple_sleeves and clitoris_sleeve where appropriate.