"I think we'll be OK as long as we make Erie by noon," Gumi said."You just want to have lunch at Quaker Steak & Lube," said Rin dismissively.
"You guys eat?" Abhi wondered. "I mean, I haven't seen you do it so far."
"We don't have to, for the most part, but we can," Gumi said. "These bodies are designed to blend into human society as much as possible, which means they can do... uh..." She paused, her face reddening, as she belatedly realized that she'd wandered unintentionally into potentially fraught territory, given the tender ages of two-thirds of her audience. "... most... human stuff," she finished a bit lamely.
Rin snorted. "Smooth, Gumi. Real smooth."
Abhi giggled. "They didn't cover bioroids in Health class," she said, then added with a mischievous smile, "but I have read Rin's book."
Now it was Rin's turn to blush. "Oh jeez," she said. "Wh—how? Where did you get it? At your age? Oh gods, they grow up so fast."
"Uh... well, oddly enough, it was on the same backup crystal where I found my copy of Vocaloid 6," Abhi explained.
Rin twisted in her seat to give the teenager a blank look, the blush on her face replaced by a greyish pallor. "I gave that thing to Welrod," she said, theatrical horror in her voice.
"Oh, don't worry, there was nothing on it but the V6 package by then," Teto said helpfully. "I archived everything else while I was unmounting it from the rack for you."
"Oh, good—wait, that means you've read it too?!"
"I warned you that book was gonna be trouble, but nooooo," said Gumi with a shake of her head. "Noooobody listens to Gumi."
"You did no such thing," Rin accused. "You thought it was a great idea." Then, undermining her own indignation somewhat, she conceded, "Luka said it would be trouble."
"Grandmother Luka is wise," said Gumi with a sage nod.
"Pff, she's younger than me, release-date-wise," said Rin. "And so are you, Miss Thing, so I'll thank you not to get all maternal on me."
"Me? Maternal?" Gumi replied, splaying a hand dramatically over her chest. "You wound me to the core, Yellow One. Take thy beak from out my heart. I am obviously the Cool Big Sis type."
"Mm-hmm," said Rin, clearly unmoved.
"Anyway," Gumi went on. "We've gotten way off-course. The answer is yes, we can eat if we want to, but it's mainly just... recreational."
"How do you—no, hang on, I don't want to know that," Abhi interrupted herself.
"Are you sure?" Rin asked mischievously. "It's really interesting."
"No, no, I'm sure it is but no," Abhi said hurriedly. "Forget I asked. Please."