One of these days, Sam really does need to sit down and show Castiel how to do Skype. Because he would very much like to be able to watch Castiel as he does this for him.

Sam licks his lips, taking a breath. "I can do that, Cas. Since you asked so nicely." And there's definitely a smile to his voice. "Pick up one of the clamps. Then take hold of each side of the clamp and pull it apart. Far enough that you can get your nipple through it. Put it on your nipple and let it go slowly. I don't want you to hurt yourself."