When you think badly written sex scenes, I think most people immediately think of romance novels. While there are many heaving bosoms and deranged euphemisms for man parts, I don't think romance novels can come come to the bizarre bedroom antics described in sci-fi and fantasy novels.
George RR Martin, Neil Gaiman, Margaret Atwood, William Gibson... these are just some examples of people who we love but have written some horrifically bad sex scenes. They aren't just bad, they're absolutely terrible. Martin's sex scenes make me shudder, Gaiman's always seem rather funny until you get to a certain part in American Gods and your faith in humanity is tested. Neuromancer is choked full of very bizarre sex between Case and Molly. These are just some examples but we can all agree that they aren't the shining points of those novels.
I ask you, faithful readers, are sex scenes necessary in sci-fi and fantasy novels? What was the worst sex scene you've ever read in a genre book? What author would you recommend to win the Bad Sex Award?