I recently finished a book that worked for me on some levels, but didn't give me a case of overall great book squee. The book, The Englishman by Nina Lewis (Omnific, 2013), focused on a young professor in her first tenure-track position at a small liberal arts college in the South, and her relationship with her mentor, a senior colleague who is older than her, and who is, in a way, her boss. One of the elements of this book that I'm still pondering is the fact that the romance was, for all intents and purposes, forbidden. Not only would indulging in the attraction between them be professionally uncomfortable, but for the heroine, Anna, it would be career suicide. She is subject to multiple reviews as she approaches the time when she can apply for tenure, and her behavior has to be above reproach. Having a wild fling with her senior colleague and mentor would be, to say the least, frowned upon. 

And, of course, that comes with a double standard—the consequences for him would have been much less severe, as he's the senior colleague, and a dude. 

Forbidden romances are a challenge in a contemporary setting, because there aren't that many obstacles that effectively prevent two people from being together nowadays. The things keeping them apart, if they're external, such as social censure or professional consequences or general humiliation, in a novel have to be be large enough to provide tension, but not so large that they can't be overcome to make room for a happy ending. Conversely, those same obstacles can't be so small that the characters' inability to surmount them makes them look cowardly and weak. 

Forbidden romance requires skill and balance on the part of the writer. Oftentimes, forbidden romances set a character's moral compass against their deepest desire and place characters in the position of doing the "right" thing while wishing fervently to yield to their own desires. Sexual tension can become scorching hot when there's a tangible element of the forbidden involved in the two individuals hooking up. Whether it's age or class difference, family feuds, professional responsibility or familiar roles that render some people off-limits (such as "best friend's younger sibling"), the "we shouldn't be doing this" aspect can make for some very hot writing. 

The forbidden element of The Englishman, as I mentioned, is that Anna and the hero, Giles, are colleagues and in a teacher/student-esque relationship. Teacher/student roles are a common portrayal of the forbidden love, as evidenced by this list on Goodreads that features a pile of "Older Male Teacher/Guardian Roles in Romance." Some are paranormal, and some are erotic, but the experienced, worldly male teaching the younger, inexperienced character (male or female) is a recurring motif. 

Forbidden romances can appear in other genres, too: A nobleman or man of socially higher status, matched with a courtesan? Definitely. Unclaimed by Courtney Milan (Harlequin, 2011) is a good example of that, as is A Notorious Countess Confesses by Julie Anne Long (Avon, 2012). Both books are historical romances featuring characters that fall in love with one another across the deep chasm of social boundaries. Guardian/Ward romances? That's a historical trope of long-standing—Georgette Heyer wrote several that are reader favorites, including These Old Shades and Regency Buck.

But the thought of crossing social chasms/class boundaries doesn't always cause a paralysis of fear among contemporary characters, and there aren't that many guardian/ward romances in contemporary settings (though my absolute favorite Maya Banks novel, The Tycoon's Rebel Bride (Harlequin, 2009), which I've mentioned here before, is a contemporary guardian/ward romance). The forbidden aspect of social consequences is explored in male-male romances, certainly, and the boundaries of law and social custom are explored in paranormal romances as well. 

But the contemporary forbidden romances I find are most often based on employment or one person's role in life that makes them off limits to the other character. Circumstances like those are not easily set aside or changed, and can create some powerful romance. It requires a sustained balance of tension and believability to pull of a forbidden romance and have it end satisfactorily after outlining all the reasons why two people shouldn't be together. When it's done well, it's delicious reading. 

What are your favorite forbidden romances? What obstacles work for you—and which ones don't work at all? 

Sarah Wendell is the co-creator, editor and mastermind of the popular romance blog Smart Bitches, Trashy Books. She loves talking with romance readers, and hopes you'll share your new favorite romance reading recommendations. You can find her on Twitter @smartbitches, on Facebook, or on her couch, most likely with her eyeglasses turned towards a book.