From Fox News:
Eight-term Indiana Rep. Mark Souder was announcing his resignation Tuesday after admitting to an affair with a female aide who worked in his district office.
Souder, a Republican, will will step down on Friday. He said in remarks obtained by Fox News that he "sinned against God, my wife and my family by having a mutual relationship with a part-time member of my staff."
"I wish I could have been a better example," he was to say. "In this poisonous environment of Washington, D.C., any personal failing is seized upon, often twisted, for political gain. I am resigning rather than to put my family through that painful, drawn-out process. ... We are a committed family but the error is mine and I should bear the responsibility. Not only am I thankful for a loving family but for a loving God."