Sibling Rivalry or Mommy Torture?

It seems that every time I nurse Harmon that inside baby (we are calling her Baby Niña now) kicks. A lot. Which always seems to make Harmon pound his hand on my belly. I'm not sure if they are playing a game, called beat on mommy, or getting a head start on beating each other. Either way, it makes me laugh and wonder what it will be like in a few short months when we will have both of them on the outside, and how much I will have to protect Baby Niña from Harmon.