The Other Man by Hilary Davidson
Billy is having an affair with a cop’s wife. When the cop starts stalking him he gets scared and tries to break it off, but the wife won’t let him. The twists in this story just pile up one on top of the other until the ending you never see coming arrives to take your breath away. A rich, fun story. You can read it here http://www.beattoapulp.com/stor/2011/0731_hd_TheOtherMan.shtm
This story is a Spinetingler Award finalist.