► 成句何食わぬ顔  [(4)なにくわぬかお]    
meaning:  pretend  rank: 3☆ 
犯人は
被害者を
殺した
後に何食わぬ顔をして
家で
家族と
食事をしていた ⇨ The suspect went home and had a meal with his family as if nothing had happened after he had murdered the victim  
(☛ Literally “ate-nothing face”. Act as if nothing happened, typically after doing something evil)