Sitting on the Bonnet

Used to describe a period of time out usually accompanied by intense torturous thinking.
Most commonly at a party where you get some alone time to sober up and decide whether to drink more, attempt to pull a bird or curl up and die.

Yo dude, you nailin' that whale tonight?
Na bruv, I dunno, I've got to go sit on the bonnet I'm battered mcnattered.

Yo bru, are you jacking off in there, let me in, I've got to pee!
Na sorry mate I'm just sitting on the bonnet in here!