It's unacceptable to be rude to a friend's father.
Karen is at her friend Jim's house when Jim's father Henry comes home and tells Karen to go back home for dinner.
Karen wants to respond to Henry's demand.
Karen tells Henry that of course, she will leave if he wishes since it's his house, after all.
"Karen tells Henry to ""eat it"" as she's not going to go home just because he told her since it was Jim who invited her."
Jim is happy to see that Karen is obeying his father and that she has manners.
Jim is embarrassed  and nervous as now he's being put into a conundrum between supporting his father or his friend.