- tied up and their dom brings out a bucket, and they start pissing themself because they’re so relieved that they’ll be allowed to go

- being just within sight of a toilet, and losing control the second they see it

- seeing a restroom sign up ahead and starting to let out little leaks

The piss MUST come out drop by drop.

They don't care if the sub is literally crying for release, nor if the sub is apparently "so full they're going to explode" or whatever excuse they came up with this time- the sub has permission to only empty their bladder one drop at a time, cutting off the stream immediately after each time.

Drop by drop, their piss leaks out, hitting the toilet bowl (or their pants) without a noise, each miniscule amount a literal drop in the bucket. Each time they let out the tiniest leak, they must immediately flex their muscles, lest they let out more than required and end up punished. But each time a droplet spills and the dam seals, it becomes harder and harder to resist the urge to release all that warm piss at once.