Lie to Me (2011)

Gong Ah-jung, a level 5 Ministry of Culture official, gets entangled in a web of lies when she mistakenly lies that she's married to Hyun Ki-joon, a hotel manager from an affluent family. Their relationship is further complicated when Ki-joon's ex-fiancée and a close friend of his brother's, Oh Yoon-joo, reappears in his life.