It's the sexy stubble on his face and how his boy's body shudders when his scruff brushes against his smooth soft skin. It's the hard taut muscles of his strong shoulder and arms as he effortlessly tosses his boy around the room. It's the beads of sweat rolling down his chest towards his hard throbbing cock. It's his deep voice and piercing eyes that reassures his boy. It's because Dad Knows Best.