As I am not a complete ignoramus I did know that grumppa.
I did get the inference. Turning social norms on their head (or backsides).
As I said, farting is perfectly natural too.
Rudeness on GN seems to be becoming the norm, too.
Fascinating causes of death 1632
Energy Firms Want Government To Step In Over Winter Bills.....
Good Morning Sunday 23rd August 2926
What’s a household item that reminds you of your grandma’s house?

. I have not seen it, only heard of it - it may have been discussed on one of those BBC arty programmes, I can't remember.