The relationship between your wife and the bitch your sleeping with.
Karl: Dude, my wife and my girlfriend started throwing down the other day.
Sam: You let them meet eachother??
Karl: Yeah I love watching their hatetationship. Oil and pillowfights.
Applies more to women. That one bitch at the office or salon you chat up to pass the time away. When she leave, you talk about how much of a cunt she is.
I always see Amanda and Stephanie talking. Oddly enough Steph wants to jam her size 8 up Amanda's vag. Must be one hell of a hatetationship they have.