She told her dad because she didn't like what she'd done and felt the need to confess and let him handle it. He trusted you with his daughter. You showed extremely poor judgment, exposed his little girl to all kinds of unnecessary risks, & betrayed his trust. Frankly, if you pulled that stunt with MY 16 yr-old child, I wouldn't just *threaten* to press charges. Perhaps if you apologize profusely enough, he'll let the matter drop. Grovel. Grovel sincerely.
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This is not legal advice and you are not my client. Double check everything with your own attorney and your state's laws.