Tantrums

Our fifteen month old son has started throwing tantrums when he feels he has been slighted, usually by his sister. The boy has some lungs and determination. Oftentimes it matters little what I do, I just have to wait for the tantrum to run its course. Lately, though, our 3 year old daughter has started telling him, very sternly, "Stop that right now. That's ridiculous." The funny thing is that more often than not, he stops dead in his tracks.