Castiel makes greedy little sounds as Sam pushes the plug into him, utterly lost to the sensation of being filled. It's unique, and it's good, a physical union that expresses what they feel for one another. Castiel wants it all.

"Yes, but... I want more, Sam. I want to feel you."

He begs, but he knows Sam will deny him for now. Maybe he just needs the verbal reassurance. He's relaxed though, not upset. Just longing for his lover.