It's one thing to make a scene with your brother in your own home, and quite another in the home of a new friend. Maybe when Thor knows Ariadne a little better he'll be barging in as though the whole tower is his own.

"Perhaps another time." His gaze sweeps the books briefly, but returns to Loki. He's on a mission, and will not be distracted. "I've been tasked with a quest by the Lady Ariadne."