Well, the suit did have plumbing, so it wasn't the first time he peed in it. Though, as we saw... Well, does anyone remember David Sedaris's article about the "Stadium Pal"?
You know, he was probably in that suit for at least twelve hours when he went to Unspecifiedistan in the first movie. Next time I watch that, I'm going to be wondering throughout the sequence if, at any point, he's availing himself of the facilities.
David Sedaris, With a Pal Like This, You Don't Need an Enemy
On top of that, I found that it was hard to pee and do other things at the same time. Reading out loud, discussing my dinner options with the flight attendant, checking into a fine hotel: Each activity required its own separate form of concentration, and while no one knew exactly what I was up to, it was pretty clear that something was going on. I think it was my face that gave me away.
You know, he was probably in that suit for at least twelve hours when he went to Unspecifiedistan in the first movie. Next time I watch that, I'm going to be wondering throughout the sequence if, at any point, he's availing himself of the facilities.