Here’s what happens when you start doing the baby sign for ‘please’ (it’s a chest-rubbing action, weirdly).
1. Henry does it. He gets some of my Cheerios.
2. Henry thinks that we’re just rubbing stuff when we eat Cheerios now, and rubs my chest instead. Good enough. He gets Cheerios.
3. Henry would rather not have Cheerios at all than make the ‘please’ sign. You can stuff your Cheerios and the spoon they rode in on.
(I’m not actually a big baby-sign advocate: Henry would always rather take the quickest route to cereal, so I can imagine that if it gets easier for him to sign than talk, he’ll sign. But I do want Grabby Sir Grabberson to say ‘please’ or something like it, so it works in the meantime.)