Cheating, Incorporated: The Infidelity Economy. "Looking to sneak around on your spouse? Got a little cash to spend? The CEO of Ashley Madison, a website whose own backers don't even want to be associated with, is happy to take your money." (Previously on MeFi) [more inside]
posted by zarq on Feb 11, 2011 - 69 comments

Cheatneutral. "When you cheat on your partner you add to the heartbreak, pain and jealousy in the atmosphere. Cheatneutral offsets your cheating by funding someone else to be faithful and NOT cheat. This neutralises the pain and unhappy emotion and leaves you with a clear conscience." [Via Gristmill.]
posted by homunculus on Feb 13, 2007 - 39 comments

Don't date him girl! Good news for the paranoid. Invasive site for documenting those unsavory men who have cheated on women. The rebuttal: warning: flash site with annoying birds. bugmenot
posted by AllesKlar on Mar 13, 2006 - 40 comments

Near Ovulation, Your Cheatin' Heart Will Tell on You "New research from UCLA and the University of New Mexico suggests that members of "the gentler sex" may have evolved to cheat on their mates during the most fertile part of their cycle — but only when those mates are less sexually attractive than other men."
posted by anyokerin on Jan 18, 2006 - 57 comments

This guy is such a dog. Misogyny, probably NSFW.
posted by xowie on Nov 10, 2004 - 55 comments

Dial-A-Cheater "proved what I couldn't. After he answered the call I scheduled, I asked him who it was. He lied. I totally busted him out. He was cheating with my best friend!" Kill the illusion of joy with a cell phone (and $1.95 USD).
posted by LinusMines on Apr 14, 2004 - 18 comments

How many times have you cheated? Did you feel sorry for it, or did you just enjoy yourself? And did you still love the one you cheated on? How many times would you have to cheat before you admit you aren't really in love with your S.O?
posted by stoneegg21 on Sep 4, 2001 - 31 comments

Mobile phones alert husbands to cheating wives
i suppose this could work both ways...
posted by bwg on Apr 6, 2001 - 6 comments