2 Samuel 13:2-4  New Revised Standard Version, Anglicised Catholic Edition

² Amnon was so tormented that he made himself ill because of his sister Tamar, for she was a virgin and it seemed impossible to Amnon to do anything to her. ³ But Amnon had a friend whose name was Jonadab, the son of David’s brother Shimeah; and Jonadab was a very crafty man. ⁴ He said to him, ‘O son of the king, why are you so haggard morning after morning? Will you not tell me?’ Amnon said to him, ‘I love Tamar, my brother Absalom’s sister.’