If it's old enough it's literature ?
Memoirs of Fanny Hill by John Cleland
John Cleland was an 18th century English novelist best known for Fanny Hill, an erotic novel that was very controversial in England during its era and has the distinction of being one of the most banned books in the world. To this day, the novel is notorious for being synonymous with obscenity.
http://www.amazon.com/gp/product/B00SAENL68/
http://www.amazon.co.uk/gp/product/B00SAENL68/
http://www.amazon.ca/gp/product/B00SAENL68/
Forbidden Fruits by (Anonymous)
"Forbidden Fruits is one of the most influential erotica novels of the Victorian Era, and it was also controversial for being so frank about sex."
http://www.amazon.com/gp/product/B00SADQZAS/
http://www.amazon.co.uk/gp/product/B00SADQZAS/
http://www.amazon.ca/gp/product/B00SADQZAS/
My Secret Life Volumes I-III by (Anonymous)
one of the most influential erotica novels of the Victorian Era, and the anonymous author used his anonymity to write both frankly and controversially.
http://www.amazon.com/gp/product/B00SAENHGW/
http://www.amazon.co.uk/gp/product/B00SAENHGW/
http://www.amazon.ca/gp/product/B00SAENHGW/