stand on ceremony
US /stænd ɑn ˈser.əˌmoʊ.ni/
UK /stænd ɑn ˈser.əˌmoʊ.ni/

1.
拘泥於禮節, 講究客套
to behave in a formal way, or to insist on formal behavior from others, especially when it is not necessary or appropriate
:
•
Please don't stand on ceremony; just make yourself at home.
請不要拘泥於禮節;就當自己家一樣。
•
There's no need to stand on ceremony with old friends.
老朋友之間沒必要講究客套。