伪称

wěi chēng duì zhè jiàn shì yī wú suǒ zhī

伪称对这件事一无所知

falsely profess total ignorance of the matter

tā wěi chēng xǐ huan nǐ rán hòu zài bèi hòu shuō nǐ huài huà

他伪称喜欢你，然后在背后说你坏话。

He pretends to like you, but speaks ill of you behind your back.