His breath faltered when she squeezed her legs, the movement doing some extremely interesting things from the inside. It was probably the best encouragement she could offer, ballgag and all, and he took to it without hesitation, the constant stream of energy from his ADHD keeping him going. He wanted to keep that feeling going, and the most obvious way was to start moving, so move he did. It's not smooth, not exactly easy, and maybe the first time he pulls back a little too far and has to reposition and start again, but it's not... bad, at least not for him.