Have you heard of this erotic science fiction novel from the 1970s?

You know when you really want to find a wonderfully naughty novel you read when you were a teenager, but you just can't think of the name or author? One io9 reader desperately needs your help to track down a long-lost (but beloved) erotic scifi novel.

This reader writes in to say:

My wife recently told me of her interest in erotic literature and mentioned a paperback she read as a teenager in the mid 1980's. She said it was the most arousing, erotic thing she had ever read and I'd like to find it for her. Unfortunately, she has no idea of author, title or even character names. She did have a few plot details that I'd like to share.

The main female character enters another "realm" whenever she falls asleep, where there is a "demon" or other type of creature that has her chained up and performs all types of sexual acts with her. The biggest detail she could share is that this "creature" has 3 penises and uses them all to pleasure the main character.

My guess is that the timeframe of publication would be mid to late 1970's to mid 1980's.

I have no idea what this book is, though it definitely sounds like something from the 70s. Do you know? Please help reunite this woman with the awesome smut of her youth!