Pop a piss

To go take a leak, pee, etc.

"Man I drank so much beer yo! I really gotta pop a piss.

Pop a piss in'

Getting in on the action, that one was originally left out from; typically a determination of one coming from poverty and into prosperity.

We're broke as mfer over here, ima pop a piss in', hands in the air, Chuck Norris style aye'

- Conor McGregor