Sforno on Genesis 39:14/ספורנו על בראשית ל״ט:י״ד

1ותקרא לאנשי ביתה, in order to justify her conduct. However, when she saw that Joseph had stopped running after leaving the room where she had waylaid him, and the fact that the people in her house had no reason to question Joseph who was acting perfectly normally, she told those people that Joseph had fled from her room and walked outside, something which actually corresponded to the truth as far as the facts were concerned. (verse 15) However, when relating what had supposedly occurred to her husband who had not been an eye witness to any part of the incident, she described Joseph’s behaviour as a flight not only from her room but also outside of it. (verse 18) In order to make her version of events believable she had to lie so that Joseph would be perceived as having tried to escape from the other members of the household.

2לצחק בנו, to take sexual liberties with us.