开某人的玩笑：指戏弄或捉弄某人，通常是为了取乐。
subject to a playful hoax or joke
同义词： hoax / play a joke on
... Get over yourself. 别自以为是 Pull someone's leg 开某人的玩笑(不是“拉某人的腿”); Between jobs 待业中(不是“在工作之间”); ...
... Blogorrhea 博客多语症 Pull someone's leg 开某人玩笑 Get a life 做点别的有益的事 ...
... head over heels in love：深爱着某人。 pull someone's leg：愚弄某人，开某人的玩笑。 a long face：郁闷（忧虑）的表情，愁眉苦脸。 ...
Pull someone's leg 开玩笑，愚弄某人 Eat one's words 收回前言，改正错话 .
So to pull someone's leg means to fool or trick them but in a fun way.
所以说拉某人的腿就是说用一种有趣的方式愚弄或者哄骗某人。