C33
Although he didn't tell Mu Bai and Mu Yuan about it, he did it for Mu Yuan and Mu Bai. It wasn't that he forgot something, but the butler did it on purpose!
Seeing that Mu Yuan's location was positioned at the hotel, Old Housekeeper didn't take it to heart, but coincidentally, Mu Bai's location was also located right inside the hotel! This had to attract some attention