Me, warning: "Val, no. Do not gallop the horses on the keyboard. Take them down and walk away."
Val, immediately protesting: "But Mommy! I couldn't hear you!"
Me, getting up and walking to the keyboard, genuinely, calmly intent, at eye-level: "Oh I'm sorry about that. Which part couldn't you hear?"Val, looking down, wanting to believe herself: "Um... I didn't hear you say... 'no.'"Me, ruefully: "Ah. Well I often have that problem, too. Unfortunately, it rarely works out in our favor."