You're standing in an empty study, it looks like. Exit the study, and take a left up the stairs. At the top of the stairs, continue straight down the hall. Keep going straight down the hall past the red vases, through the door, and into a bedroom with a floor mirror. To the left of the king bed is a little archway. Walk towards the archway, and through the archway, there's a door on the left that leads to the bathtub. Stand at that door, and you're done.