NET
2 But Amnon became frustrated because he was so lovesick over his sister Tamar. For she was a virgin, and to Amnon it seemed out of the question to do anything to her.
Darby
2 And Amnon was so vexed, that he fell sick for his sister Tamar; for she was a virgin; and it seemed difficult for Amnon to do the least thing to her.
KJV
2 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.