YOU SAID:

My dad told my sister that he had never told her mom who was the guy who betrayed the dog.

INTO JAPANESE

お父さんは妹に、犬を裏切った男の母親には一度も言ったことがないと言った。

BACK INTO ENGLISH

The dad told his sister that he had never told the mother of a man who betrayed his dog.

INTO JAPANESE

お父さんは妹に、自分の犬を裏切った男のことを母親に一度も言ったことがないと言いました。

BACK INTO ENGLISH

The dad told his sister that he had never told his mother the man who betrayed his dog.

INTO JAPANESE

お父さんは妹に、自分の犬を裏切った男を母親に話したことがないと言った。

BACK INTO ENGLISH

The dad told his sister that he had never told his mother the man who betrayed his dog.