Conversation so far:
What can you tell me about the films development?
The magazine's founder Bob Guccione wanted to produce an explicit adult film within a feature film narrative that had high production values.
What idea did he have in mind?
he decided to produce a film about the rise and fall of the Roman emperor Caligula.
Where was the movie developed?
The men's magazine Penthouse.

Question: why was it developed there?
Self-contained rewrite: why was Cailgula developed in Penthouse?