Walter opened the door slowly and made sure that it didn't make any sound. He knew that Tracy was a very sensitive person and would react to any tiny bit of noise.
He was sure that if not that she feared that the phone would get splashed with water she would've definitely taken it with her to the bathroom. He didn't know whether it was her paranoia or just her being in love with her phone but Tracy never left her phone behind.
It's usually said that a man's heart is where his money is but for Tracy it was where her phone was. Walter took steady steps as he listened to the sound of splashing water coming from the bathroom. He drew a long breath and puffed his chest out.
He had to do whatever he had to do to help Bernadette claim custody of him. He didn't like Tracy and he didn't want to live with her. He had been obedient in the past because it was the only way he could make her keep his sister in the house.