Castiel does not know how to explain kissing...
God and Castiel sat upon a rickety wooden bench. There was an asphalt path in front of them, and a plaza across that. Children ran and laughed, their parents following them with smiles on their faces. God had watched this group of people for a very long time. She'd found a pattern in her children. When it came to humans, parents were nearly always smiling while chasing their offspring.
After a while, something God had not seen before caught her eye. A young man and a young woman were embracing across the plaza. The young man wore clothes with spots of green and brown, as well as large boots and some sort of hat. The woman wore jeans (much like the pair God was wearing) and a T-shirt.
The two stood like that for a decent amount of time. God did not understand why. Then she found herself even more confused when they separated and pushed their mouths together.
"Castiel," God began, cocking her head as she continued to watch the couple. "Of what benefit is that?"
Castiel looked up from his hands, and followed her gaze. His face flushed momentarily. He'd never thought he would have to explain this to her.
"Um… The humans use it as a means to show affection," he uttered. He felt awkward, which was a sensation he hardly ever felt.
God nodded, and Castiel thankfully went back to examining his vessel's hands. He never got bored with them. The lines on his palm were enough to keep him distracted for hours on end.
"Castiel?"
He sighed, and his eyes shifted to God once more. He hardly had time to register her movements before she pressed her lips against his. It was brief, and Castiel thanked the holy spirits for that. However, it still shocked him. His shock wavered when she patted his arm and rose to her feet.
Castiel reached out and snatched her wrist. "Where are you going?"
"I wish to show Samuel and Dean my affection for them, as well," she said with certainty in her voice.
He pulled his creator back onto the bench, once more feeling his vessel's face flush. "That act shows a much more… meaningful kind of affection," He stated, his blue eyes shifting to the asphalt path in front of them.
"I do not understand."
He sighed. He did not feel he was expressing this correctly. "Humans feel love –"
"As do I, Castiel."
"Yes, but this is a different kind of love," he reached up and ran his hand over his face. "For many humans, to be in love means to mate."
God finally understood. "I apologize for my actions, Castiel," she muttered as her eyes widened. "I do not wish to mate with you."
Castiel nodded, but avoided God's gaze. "Perhaps we should return to Sam and Dean…"
God nodded in agreement, and the two quickly returned to the dirty motel room on the other side of the continent.