I don't think you're teaching your kids not to lie. You are teaching your kids the situations the community you're in has decided when it's okay to lie and when not. We package this as this sort of absolute philosophy but it's not. It's very flexible and hard to navigate.
You have probably lied to your kid that you're out of snacks or that you forgot to bring your wallet to buy more snacks. Or that Santa exists. Kids will eventually pick up on these things.
Yet you created a new account here just to bitch about that. What does that make you? The petulent teenager?