Am in their bad books - Idioms by The Free Dictionary
be in (someone's) bad books (redirected from am in their bad books)
be in (someone's) bad books
To have fallen out of favor with someone due to having offended or mistreated them. I don't think I'll come to the party on Saturday because I'm in Jenny's bad books at the moment.
be in/get into somebody’s ˈgood/ˈbad books (informal) have/not have somebody’s favour or approval: I’m in his bad books at the moment because I accidentally broke the window. ♢ ‘Why are you cleaning her shoes?’ ‘I’m trying to get into her good books!’