2 sentences

1. 他只能无奈地苦笑。

   tā zhǐ néng wú​nài de kǔ​xiào.

   He could only give a helpless, bitter smile.

   Source: Dong Chinese Dictionary

2. 面对这种尴尬的局面，他只能无奈地苦笑。

   miàn​duì zhè zhǒng gān​gà de jú​miàn, tā zhǐ néng wú​nài de kǔ​xiào.

   Facing this awkward situation, he could only give a helpless bitter smile.

   Source: Dong Chinese Dictionary