laugh on the other side of one's face

... keep a strange face 绷着脸，忍住不笑 laugh on the other side of one's face 转喜为忧 on the face of it 就表面判断 ...

... lol：laugh out loud （短信用语） laugh on the other side of one's face 转喜为悲 hold one's sides with laughter 捧腹大笑 ...