I thought it might be a good idea to teach Leo "no", or "nee" in Dutch. Sometimes when I'm feeding him, he spits out his food with great delight. Funny for him but not conducive to a expeditious feeding.

So I thought it would be good to tell him, in a stern voice "nee".

Well... now he thinks that "nee" is a joke, and actually starts making spitting sounds when I tell it to him, even if there's no food.