He kept the glee off his face, instead letting a quiet captivation with the dance steps show through. Wouldn't do to get too cheeky; that was for later.
Hip-swing step-back. "Oh, you seem to have the bulk of it down already..."
And a slight lean forward, just enough to bend Booster's back a bit, coming up into a fast twirl about that let him switch hand positions. "Wanna try the lead? It's been a while since someone dipped me."