阴阳怪气

yīn yáng guài qì

snide; needling in a sweet voice

Character by character

阴yīn
yin

阳yáng
yang

怪guài
strange

气qì
air

有话就直说，别阴阳怪气的。

If you have something to say, say it straight; do not be snide.

Tone: negative (criticism).

Learn this in Lesson 213 · HSK 9+: 弦外之音 (What is left unsaid)

A dialogue, a reading, word cards with audio and a drill that uses it, in Learn Chinese with Bao. The first lessons of every level are free.