Katoptronophilia is a paraphilia for mirrors (the Greek word for mirror is katoptron). It may include activities such as having sex in front of mirrors, masturbating in front of mirrors, enacting other paraphilias in front of a mirror, having an orgy in front of a mirror, or enacting stripping fetishism in front of mirrors.
Enacting katoptronophiliac fantasies may involve constructing environments for erotic activity in which one is completely surrounded by mirrors, sometimes including even on the ceiling. A person who is a katoptronophiliac may put mirrors all over their house so they can have sex in any room in the house.
Many pornographic films show porn stars having sex in front of mirrors. Many people enjoy having sex in front of mirrors and have mirrors in their bedrooms in which they can watch themselves have sex. Katoptronophilia would seem to be a benign, non-controversial and basically harmless paraphilia.