"I am not very good at keeping secrets at all! If you want your secret kept do not tell me!"

Miley Cyrus is alerting her audience that she is not the best individual to tell secrets to. She is implying that if somebody wishes to keep a trick, they need to not tell her. This might be translated as an indication of her sincerity and integrity, as she is not happy to keep secrets that are not hers to keep. It might also be translated as a sign of her trustworthiness, as she is not happy to betray the trust of those who confide in her. Additionally, it could be analyzed as an indication of her regard for the personal privacy of others, as she is not willing to breach their trust by sharing their secrets. Eventually, Miley Cyrus is sending out a clear message that she is not the best person to tell tricks to, which if someone wishes to keep a secret, they need to not tell her.