Dean's very distinct and off-key voice echoed through the apartment. He was definitely singing Metallica, but softer and more melodic than he usually sang. Summers follow his voice into the bedroom. He held little baby Robert in his arms as he sang.
"You are not singing Metallica to our baby, are you?" she asked.
Dean looked up and smiled, then kept on singing.
Summers sat down on the bed and shook her head. She should have known what she was getting into when she procreated with Dean Winchester. By the chorus, though, she could not help herself from joining in.