Initials standing for the term "In House Pussy" used to describe when a woman is living with you.

Anatidaephobia is defined as a pervasive, irrational fear that one is being watched by a duck. The anatidaephobic individual fears that no matter where they are or what they are doing, a duck watches.

Anatidaephobia is derived from the Greek word "anatidae", meaning ducks, geese or swans and "phobos" meaning fear.

IHP = In House Pussy
Girlfriend or fuck buddy that lives with you.