Cam stood off to the side, watching Vala's splash fight with something a bit like jealousy, though he wouldn't have actually acknowledged it as that. He remembered the other day, doing the same thing with her, thinking the same thoughts Dean is thinking now - how nice it was to smile, and how good Vala was at making him do it... in those moments when he wasn't actively wanting to strangle her.
He turned away when he saw Dean pick up Vala, not wanting to interrupt.