1
general::
Phrase(s): keep on the right side of someone [and] keep on the good side of someone; stay on the good side of someone; stay on the right side of someone
Fig. to remain in someone’s favor. (This has nothing to do with the right-hand side.) • You had better keep on the right side of Mr. Franklin. He’s very particular. • I will keep on the good side of him.
McGrawhill's American Idioms And Phrasal Verbs