The expanding balloon under me is one of my favorite things :) I asked Lilu to take an electric pump, attach its hose to the red 36'' balloon and turn the pump on. The pump is fast so I had just a couple minutes to enjoy the extreme pleasure of riding it and feeling how tight it becomes...before it bursted under me!! Now it's Lilu's turn, and she's eager to straddle clear 36'' balloon and go the same way... ;)