Dean can be very stubborn when he doesn't get his own way, as John has discovered. He also doesn't like it very much when he thinks his baby brothers are getting more attention than him, which is why even when Sam called shotgun this morning, Dean shoved his brother over and blitzed out the door of their motel room in a haphazard dash to reach the Impala's passenger side first.
"Where does it hurt, Sammy?" John asks as he kneels down beside his middle son, pushing a hand back through those adorable bangs of his.
Sam sniffles and points down accusingly at his hip. "Here."
"I'm sure Dean will be sorry when he sees what he's done to you," John says smoothly, and straightens Sam's too soft hair back into its original place.
"I can kiss Sammy better," little Adam pipes up, his eyes bright.
"You wanna kiss Sammy better, Adam?" John asks, a warm smile greeting his lips. He's primarily angry with Dean for being so rough around both Sam and Adam, but his youngest always knows how to brighten his day, in that naïve way of his.
Adam nods. "I can kiss his hip for him," he tells John. This makes Sam giggle, and John has never been more proud of Adam. John takes the hem of Sam's tee in between his thumb and forefinger, lifting it carefully. Adam ducks his head and puckers up, before he places a subtle, damp kiss to Sam's left hip. When Adam lifts his head back, he meets Sam's eyes and both boys are smiling like they've shared a deeply intimate moment.
A familiar warmth floods through John's stomach, and he isn't simply admiring Adam's sensitivity. No, Sammy's shirt is still risen a couple of inches, revealing soft, milky skin that has never touched by anyone other than his little brother, who's pink lips are a little wet. Adam reaches across and entwines his fingers with Sam's. Sam responds by squeezing Adam's hand, and leading his little brother out towards the car.
That heavy heat lurking in John's abdomen is nothing other than arousal: plain and simple.