2 Samuel 13:2-3

And Amnon was so vexed, that he fell sick for his sister Tamar; for she {was} a virgin; and Amnon thought it hard for him to do any thing to her. {Amnon thought...: Heb. it was marvellous, or, hidden in the eyes of Amnon} But Amnon had a friend, whose name {was} Jonadab, the son of Shimeah David's brother: and Jonadab {was} a very subtil man.