J.M. Roberts 
The Triple Trap [EPUB ebook] 

Junes invited to work, by her husband, to join a colleague, undercover in a drug bust.
Without her husband knowing, shes enticed into snorting cocaine and working as a whore.
Her colleague teaches her how to fake an orgasm, a client assists her to achieve a real orgasm.
With a drug habit and a sexual desire, June agrees to meet the client whos satisfied her.