When a mom or dad (mostly a dad) secretly enjoys playing with his son or daughter's toys and watching cartoons and feeling like a child again but pretends he or she is just doing their parental duty.
Friend 1- "Whatcha doing watching Hannah Montana and playing GI Joes, bro?
Friend 2- "Oh, you know, gotta do the parental duty. ho-hum"
Friend 1- "dude, your kids left the room an hour ago. You're such an imposterparent."
Friend 1 (sitting down)- "Is this the episode about Hannah stealing? Give me Cobra Commander over there, man."