Pigsy walks off, and Monkey discreetly sniffs at his armpit.
Pigsy reveals to Monkey that he's had a thing for Trip, to which Monkey replies...
"Pigsy? She can hear every word we say."
Right when the main characters use an escape pod after their ship blows up. They are all tightly cramped together, which leads to the following conversation:
Pigsy: "Um, Monkey, could please try to shift your left hand?"
Monkey: "I don't really see how I can."
Pigsy: "It's just that your hand is resting...right on my...penis."
The expression on Pigsy's face is what really makes it so damn hilarious. There's also the Oh, Crap! expression on Monkey's face after Pigsy points out where the former's hand is.
When Monkey, Trip, and Pigsy are inside the Leviathan