good/bad form
bad form
Behavior or actions that are considered socially inappropriate, distasteful, or rude. Many people still consider it bad form to ask a woman her age.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
good/bad ˈform
(old-fashioned, British English) a way of doing things that is socially acceptable/not socially acceptable: I think it was very bad form for Joe to arrive late for the funeral. ♢ Apparently, good form requires you to wear a hat on these occasions.Farlex Partner Idioms Dictionary © Farlex 2017