The look on Castiel's face doesn't escape Sam in the least. He smiles, shucking off his shirt and laying it carefully over a nearby chair. Then he takes a moment to look over Castiel, fingers twitching with the desire to reach out and touch.

Something he doesn't stop himself doing, really, though he should get his trousers off, at least. Instead, he steps forward, brushing his fingers over Castiel's cheek before his hands slide down, gently stroking over Castiel's shoulder and down his chest.

It takes another moment before he raises his eyes to Castiel's face again with a smile. "You can touch, too. If you want."