互不相容

lǐ mào hé shí huà cháng cháng hù bù xiāng róng

礼貌和实话常常互不相容。

Politeness and truth are often mutually incompatible.

zhè liǎng gè gòu xiǎng hù bù xiāng róng

这两个构想互不相容。

These two ideas are antipathetic to each other.