New Cartoon idea

Bill here.
This is just off the top of my head, but here's a gag cartoon idea I just came up with:
Teenager helping frail old lady across the street.
Halfway across, the light turns green.
Teen begins to change direction and says to old lady "Sorry, I gotta run, the lights changing."

I don't know. I'll have to see how it translates to paper. It's my usual modus operandi to
write ideas in text form and then have brother Bob send me a pencil sketch, which I will
later put to pen and ink .

We'll see if this develops...
-B