My bad, your fault
When one person makes a mistake, but admits fault while placing the blame and/or responsibility on someone else, mostly to avoid responsibility while often putting the scapegoat in an awkward situation.
Derek: Damn, man. Not only did Alan forgot to tell me that a specifications changed and all the work that I did this week is now useless, he asked me to do mandatory overtime this weekend since apparently it’s his turn to have his daughter, and he threatened to fire me if I told management what really happened.
John: So a "my bad, your fault" situation. What a jackass!
John: So a "my bad, your fault" situation. What a jackass!