Radar Magazine has a great and funny article on the 100 ways to tell the relationship is no longer working - and it is their fault...
My favorites:
6. The erotic highlight of your week is "Whip It Out Wednesday."
19. She keeps accidentally stabbing you.
NO. 37 At your high school reunion, you introduce him as "the reason I'm on Paxil"
38. Your respective Christmas stockings say Shrew and Let's end this charade, Doug.
53. Your response to "Does this skirt make me look fat?" is "No, your giant ass makes you look fat."
57. Out of nowhere, the cashier at the supermarket says, "Don't worry, five inches is almost average."
64. Although not a special occasion, you sometimes call just to whisper, "You've stolen my youth."