“I don’t understand.”

“It’s really simple. I live in your stomach and intestine and help regulate your digestive process. Unlike your normal gut bacteria, I can’t be killed off by antibiotics, so you don’t have to worry about getting sick.”

“But—” I was going to say “that’s not even possible.” Then I remembered whose head had been poking out of my butt half an hour earlier. “—how does that work?” I said, lamely.

“I was skeptical at first, too,” Cindy Lou said. “But now that I’ve tried it, it’s not bad. Like sleeping in a nice warm bed you don’t ever have to get up from. Well, except I have to come out once a month to discharge wastes.”

“Um…look,” I said. “I really don’t think I need—”

“You know, I took a good look at your tummy on the way down, and you’ve got some prime ulcer territory there. You need me to take care of it so it doesn’t get any worse.”

“But—”

“Also, since I’m adapted to you now, I’ll die if you don’t let me back in.” She smiled brightly at me. “Do you want that on your conscience?”