Did you floss your teeth?
Wait a minute. Did you? [making eye contact]
No. [Sighs. Turns on her heel for the bathroom]
I'm confused. Why would you lie to me about that? [following her] Do you realize that when you lie to me it interferes with my ability to have confidence in you about other things?
Mom, you say it's better if we lie and then tell the truth instead of just lying, but I do that and you freak out about it.
Wait a minute--it's not good to lie-and-then-tell-the truth. What would be good is if you just told the truth in the first place.