The charm exuded by vulnerability

By the time Su-Jin leaned over to check him, Ji-Won's face was already covered in cold sweat. His clothes were all crumpled due to all the squirming, especially the white shirt. The knot of his tie was loosened and the lapels were pulled apart, revealing his collarbone. 

Su-Jin's eyes moved away from that patch of unblemished patch of skin and traveled up along Ji-Won's neck. Her eyes lingered on his Adam's apple, staring as it bobbed up and down. Every time he tried to swallow, his neck would contract, highlighting the lean muscles. 

At that moment, Ji-Won let out another groan, his mouth twisting slightly. 

The sound attracted Su-Jin and her eyes instantly moved towards Ji-Won's lips. They were even paler than before, and slightly curved downward in a grimace of pain.