Ge Fordge's Compenydyum of Sex Majick
A Grimoire stored under a lot of gently steaming crushed ice in the Library of Unseen University.
This is of an order with The Joy of Tantric Sex with Illustrations for the Advanced Student,by A.Lady, where the strict rule is that the grimoire may only be accessed by wizards who are over eighty and, if at all possible, already dead.
Kept under exceedingly plain covers.