Castiel didn't notice the Doctor leaving; he had closed his eyes, savoring the motion of the waves lapping at his chest. The water was cold but the ebb and flow of it rocked his vessel gently, like crooning lullabies to his vessel's primal human senses. He didn't bother to block the sensation as an angel normally would, letting it soothe him.
Lydia had a nice laugh. He liked hearing it, liked this moment, where no one was angry or shouting or bleeding. Smiling distantly up at her, and ignoring the fact that his fingers were dripping seawater, he reached out and pulled a marshmallow from the offered bag. He rolled the soft, powdery treat between his fingers, squishing it until it split and made a sticky mess of his fingertips.
"No, I haven't," he said, "Is it meant to be roasted? I know humans often must cook their food to make it safe." He pushed the whole thing into his mouth, scraped it clumsily off his fingers with his teeth. The flavors burst across his vessel's tongue, but they didn't do very much for him - his angel senses were too powerful, picking the taste apart molecule by molecule, sucrose, sodium chloride, starch, fructose, gelatin... "The texture is... interesting," he tried, his face scrunching up as he chewed the squishy-sticky-slimy thing.