Preschoolers can sometimes be moody when things don’t go their way.
A child’s mood can change quickly, from joy to anger, for example, if someone doesn’t pay attention to him or if he can’t make a toy work the way he wants.
Often you may not even know why he’s upset. He may have some idea inside his head of what he expects. When his expectations aren’t met, he might pout or stomp about without ever letting you know why.
Try to put yourself in his shoes. See if you can figure out the problem. “I’ll bet you’re mad because you got tired of waiting for me to get off the phone.”
Be sympathetic, even if you think his reason for being in a bad mood is not important. If he feels you understand, he’ll get over his moodiness more quickly.