费口舌

rú guǒ nǐ bù shì zhēn de gǎn xìng qù gàn má fèi kǒu shé dǎ ting ne

如果你不是真的感兴趣，干吗费口舌打听呢？

Why bother asking if you're not really interested?

bù yòng fèi kǒu shé le nǐ yǒng yuǎn shuō fú bù liǎo tā

不用费口舌了，你永远说服不了她。

Save your breath, and you'll never persuade her.