how to delete an ibook from icloud

I downloaded an embarasing erotic ibook and now it shows up on my kid's ipods, my wife's ipad. I know you are thinking what an idiot and he deserves it, however now that I have been caught and shamed by my wife the joke is over. Now I just want to get rid of the **** thing but no matter what I try it won't go away from the purchased section of ibooks.

Does anyone know of a way to delete a purchased book so it is gone forever?

Thank you,

Gilles...