I'm bored. They're bored. I'd love to give them a messy art project, but I don't want to clean up the mess.
Inspiration strikes. I set up the porch and invite them outside - there's a muffin tin of paint, a wide selection of brushes, pieces of paper laid out, ready to receive the fruits of their imagination.
They leapt to their feet with even more excitement than I had anticipated, ran out the door, grabbed brushes with gusto. Hey, mom's a genius!
What I said: "hey, guys, want to paint on the porch?"
What I meant: "hey guys, want to apply paint to paper while hanging out on the porch?"
What they heard: "hey guys, want to apply paint to the porch itself? "
I realized this as they both loaded up their brushes and headed for the railing. The English language is so imprecise! "WAIT!!!" I yelled. They froze. Then I reconsidered. Huh. Painting on the porch. What could happen? The porch gets colorful. That's fun. Maybe it washes off in the rain, maybe it doesn't. Maybe it doesn't come off until sometime when I powerwash and restain it. So?
Go for it.
And they did.