尔虞我诈

ěr yú wǒ zhà

lit. you hoodwink me and I cheat you (idiom)

fig. each tries to outwit the other; deceit and treachery

尔

ěr

thus

虞

yú

(literary) to expect; to anticipate

我

wǒ

I; me; my

诈

zhà

to cheat