on their best behavior

phrase

: exhibiting proper behavior

The children were all on their best behavior at the museum.

Examples of on their best behavior in a Sentence

Recent Examples on the Web

Everybody was on their best behavior Monday night, with the possible exception of one crucial play, and the clutch shot-making of Jokic and Shai Gilgeous-Alexander more than sufficed as great theater. — Bennett Durando, Denver Post, 10 Mar. 2026

Either Silvia and Guojun were not aware that parents under supervision must be on their best behavior—out of love for their children and fear of the state—or this was their best behavior. — Ava Kofman, New Yorker, 9 Feb. 2026

Boston Police Commissioner Michael Cox is letting students know about some preparation the department is doing ahead of Super Bowl weekend — and advising them to be on their best behavior. — Colleen Cronin, Boston Herald, 6 Feb. 2026

At the beginning of a relationship, everyone is usually on their best behavior, which can make this valuable green flag hard to spot early on. — Baya Voce, CNBC, 27 Nov. 2025

Rhymes for on their best behavior

• behaviour
• havior
• savior
• saviour
• misbehavior
• misbehaviour