It's a very mean trick.
But they're so damn cute in the meantime! I'm almost wanting another one already, even with my two hellions tearing my house apart. Almost.
To answer the OP, my belly button got really itchy at a certain point. Mine never popped, it just stretched and stretched until it was basically flat. I also have a pierced belly button, and it was pretty uncomfortable where it's pierced, I'm guessing bc it doesn't stretch as well in that spot.