If I gave you a sandwich that fell in the mud and smells bad, would you eat it? Of course not! You'd say: "Yuck! Gross!"
The Bible says a lie is just like that dirty sandwich. Whoever is wise and a friend of Jesus hates lying. It's not just that they don't lie, it's that they don't even like hearing lies. Whoever lies ends up with a "bad smell" (feeling ashamed), but whoever tells the truth has a nice clean smell!