Spanking hanky panky

Every year, Britain holds a unique literary event, the Bad Sex Awards, designed to honor the novel containing the worst description of the forbidden act. The goal of the prize is to "draw attention to the crude, tasteless, often perfunctory use of redundant passages of sexual description in the modern novel, and to discourage it." This according to a short column in this Sunday's NY Times.
This year's nominees included Jonathan Franzen, whose otherwise well-written The Corrections includes the unfortunate scene in which Chip engages in "sexual congress with his red chaise-longue." Personally, I think any writer would do well to avoid the use of the phrase "sexual congress," except when attempting satire, or in legal proceedings.
The winning passage this year came from Christopher Hart's Rescue Me:
"Her hand is moving away from my knee and heading north. Heading unnervingly and with a steely will towards the pole. And, like Sir Ranulph Fiennes, Pamela will not easily be discouraged....Ever northward moves her hand, while she smiles languorously at my right ear. And when she reaches the north pole, I think in wonder and terror...she will surely want to pitch her tent."
Writing sex scenes is never easy, and in fiction writing classes in college, professors always warned students about the common pitfall of writing such scenes: don't be too clinical, but also don't engage in hyperbolic metaphor in an attempt to capture the raptures of lust. Any attempt inevitably toes the line of between eros and camp.
But, maybe because we were college students and our teachers did not wish to engage in sexually frank discussions, we were never given hard and fast rules, or examples of well-written sex scenes. In general, I think were discouraged from writing them, and the embarrassment of having to share such scenes with our peers was enough of a deterrent to prevent the situation from arising.