Gender inversion phase?

My three year old boy is really enjoying inverting genders at the moment. At first it was fun, but it's getting really annoying. Every time I read a Peppa pig book, George has to be Baby George xx, or baby George xx Princess, and Peppa is Peppa XY prince. When we say George is a boy, sometimes he doesn't care, sometimes he gets upset.Sometimes he also does that in references to us. When we say "he" about him he does "but I'm a sheeee", and dad is xx, mum is XY, etc...I'm not concerned about him not being happy being a boy and wanting to be a girl, I'm just getting frustrated by this. Anyone else had this? via /r/Parenting https://ift.tt/2rfKKDg