Well, that’s not quite what I had in mind, but as a friend of mine likes to say, you get the steak and I’ll have the fish and we’ll call it good a night out 
You, good sir, are a very naughty boy. SMACK!
(That will be 3.99 for the first minute, .99 for each additional minute. Some restrictions may apply.)
I thought of another one: The Northern Girl by Elizabeth A. Lynn. I’m guessing that Ms. Lynn is wunna dem der homerseckshuals, since all the sex scenes in this trilogy (and there seemed to be about one or two good ones per installment) are same-gendered (and no, there is nothing wrong with that…these books were simply my first introduction to said concept).
Fits this thread for two reasons: The cover painting by Eric Ladd of Sorren, the main character (which I found inexplicably sexy for some reason…anybody know where I can snag a poster or a good wallpaper of this?), and the scene she has with her girlfriend.
Sorren was HOT.
Hopefully none of the books in this thread were appropriate material for kids, and therein lay the sweaty-palmed delight of illicit discovery. Kids today - spoilt with this new-fangled intramaweb, I tells ya. In my day we took our jollies where we could find 'em.
Found mom’s copy of Sign of the Scorpion when I was a young teen.
Star Trek books: Imzadi, some of the early DS9 books, others.
My mom had a lot of Old West-themed romance novels. Dirty cowboys and innocent farm girls, that sort of thing. She also was an avid consumer of Silhouette and Harlequin romances. In turn, I was, er, enriched by her purchases. Also, another person for Clan of the Cave Bear and its sequels, though I never felt quite the same about those books after a certain ex of mine told me he read them and considered Jondalar his role model. Snerk.
honeydewgrrl, The Shelters of Stone isn’t that great, true, but do you want a copy? Send me an e-mail if so. I managed to get rid of the other books but that one’s still hanging around.
“When Younger”?
When I was about 10 or so, I picked up my dad’s copy of Dune and flipped it open to a random page. Someone was damning fate and his inamorata’s nipple was getting hard under his hand. I’ve never been able to find that page again. 
That’s okay, because so does Ayla. She invented it, in fact.
I remember a friend’s dad bought “Naked Came The Stranger”…and then we got our grubby 15 yr old hands on it