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

1.
fare complimenti, fare cerimonie
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.
Per favore, non fare complimenti; sentiti a casa.
•
There's no need to stand on ceremony with old friends.
Non c'è bisogno di fare complimenti con vecchi amici.