This is one of my favorite situations. I'm presuming that maybe they've gone to the store for more beer, and he didn't bother to pee before they left "because I can hold it until we get back." He's at the pee-dance stage, so I'd guess it's pretty urgent.
This fellow needs to pee but his passenger apparently doesn't, perhaps because of one or more of the common male failings. He finished off all the coffee in the carafe before they set off on their trip. He didn't bother to pee beforehand "because he didn't have to go". While he was filling the car with gas, his passenger used the rest room, but he didn't pee "because he could hold it until" they got to their destination. There are more.....
