"I don't know why I was unable to anticipate such an obvious response."
"So, where would I find Gus's tavern, if I'm looking for a meal? And does that, by any chance, cost anything?"
Oliver isn't sure if he's meant to sleep in the cabin overnight, but he'd be surprised if he's actually meant to bathe in the pond. He's also at least a little concerned about what happens if he leaves his luggage inside the cabin, though he supposes it does have a door that locks... well, if they were actually out to commit crimes at him, he'd need to worry about rat poison in hamburgers too.
Whether or not the food at Gus's tavern is "free" seems potentially informative about how much of a fun prank this all is.