Paddy Caking is when you're doing a girl doggy style, and while your still inside her, you start playing Paddy Cake on her ass.
My girlfriend slapped me across the face after I started Paddy Caking her.
Actively engaging in activities that are either extremely boring, or unimportant.
Person 1: "How come you weren’t at the kegger last night bro?"
Person 2: "I was Paddy Caking with my girlfriend. She made me go see the Time Traveler’s Wife"