it is when you do something outrageous and deny it fervently to avoid guilt or consequences; then later admit you might have done it
guy 1: "so some asshole told her i banged her mom and i was like, babe you don't really believe that right! and she was like, oh i guess not. then at dinner i was like, girl, did i tell you how hot your mom is when she comes! haha"
guy 2: "man you really pulled an oj simpson on that one"