Surprisingly, there is actually a wiki page on the matter:
Wikipedia.org - Taking the Piss
Roughly covers the following:
1
- mocking someone
- making a joke at someone’s expense
2
- saying/doing something unbelievable
- doing something unfair
- taking more than your fair share
“Are you taking the piss?” is pretty similar to “You’ve got to be joking, mate!” or “are you fucking kidding me!?!”
CandleTiger@programming.dev 2 days ago
Taking a piss means going to urinate.
Taking the piss means screwing with someone, specifically by saying stuff you don’t believe as if you believe it.
I’ve never heard any variation on this phrase to mean loafing around as a euphemism, but taking frequent bathroom breaks is definitely a time-honored way of avoiding work.
Full disclosure: I am not British
vext01@lemmy.sdf.org 1 day ago
The second meaning is “you are pushing your luck”.
Hossenfeffer@feddit.uk 1 day ago
Taking the piss can mean going too far with some form of poor behaviour, usually at work, eg taking a two hour lunch hour might be taking the piss, or sparking up a joint during a ciggie break.
But it can also be in a social, non-work content: “It’s fair enough to ask for petrol money, but Bob was taking the piss when he asked for a quid a mile, the cheeky cunt.”