Call His Bluff
"Parents must confront their child or teen when lied to, or if their kid lies to someone else," urges Dr. Fran Walfish, a California-based child psychotherapist. "Accountability is the most important aspect of the act of lying. In other words, kids must own up to their actions and behaviors in order for truth-telling to be their norm."
Still, there are ways to call your kid's bluff without embarrassing him. Instead, do it gently and give him a chance to come clean. Try, "I know you said you didn't have any homework, but is there a chance you could have forgotten about your math assignment?" Taking a gentle approach lets your child know you're not trying to "catch him in the act" but you are giving him a chance to fess up.