To take off one's pants before farting

脫褲子放屁

[PinYin] Tuo1 Ku4 Zi3 Fang4 Pi4

Do something unnecessary.

When your fart, do you need to take off your pants? Of course not. We use this slang to describe someone when he does an unnecessary act. Vulgar, perhaps, but vivid and funny.

[Example]
明明就有線上請假系統可以看，老闆還是規定每個人請假要交假條，真是脫褲子放屁。
Despite the existence of online submission system, the boss still requires everyone to give him an application paper for leave. That is so unnecessary.

[Joke]
A foreign friend of mine once felt puzzled about this slang and asked why one need to take off his pants before farting. We asked him to guess the meaning. Then he said it must me "Be careful", because you never knew if you would meet a shit pretending to be a fart! :D Well... it makes sense, right?