My first encounter with dishonesty revolves around marbles.
I beat an older kid, easily. He wants to play again but I've taken his only marble. He offers a deal: spot him his marble back. If he wins he keeps it; if he loses, tomorrow he'll give me a steelie boulder he'll bring from home.
Again I beat him easily.
Tomorrow and afterwards he avoids me. First lesson in faithlessness: he never brings that steelie boulder, and he never speaks to me again.
Welcome to the world, kid. You're in second grade and you've learned that people lie, cheat, and steal.