A diamond accessory meant for a pierced vagina. A diamond stud/hoop/ring that is inserted into the pierced hole of a vagina.
Purpose is to make the vagina look very expensive. Having a kitty diamond will increase the threshold of a woman's expectations of how much a man must grovel and treat her like the bad ass Queen that she is.
"I was unable to keep my erection with that girl last night because her kitty diamond scared me away. Too much pressure!"
"Her kitty diamond forced me to spend an extra 10 minutes of cunnilingus."