keep up appearances
US /kiːp ʌp əˈpɪr.ən.sɪz/
UK /kiːp ʌp əˈpɪr.ən.sɪz/

1.
体裁を保つ, 見栄を張る
to pretend to be happier, less poor, etc., than you really are, because you do not want people to know how bad your real situation is
:
•
Despite their financial struggles, they tried to keep up appearances for their children.
経済的な苦境にもかかわらず、彼らは子供たちのために体裁を保とうとした。
•
She always dresses well to keep up appearances, even when she's feeling down.
彼女は気分が落ち込んでいる時でも、体裁を保つためにいつもきちんとした服装をしている。