Enough with those pee jokes. They weren't funny the first time, they aren't funny now. God, the story will have been way much better with the runninh gag of "Ahah Hagane want to pee". She is a JK for fuk sake not a kid or a old person.
I would actually really like to know if it's really the author's fetish or if an editor told him to shove more of it in there because people reacted to that part in the first chapter. I say that because it didn't really feel out of place in the first chapter, it was a joke but it was also a way to show just how much she didn't want to leave the cockpit.