A quiet groan escaped Kirk with that squeeze, his cock throbbing a little bit. He was taking a major gamble with all of this - he had no idea if Bones would even like this sort of thing. Or maybe he was taking it too far (...they had had an orgy but hey, this was different!).

It was a major gamble in the area of trust, too. He knew the knots he had tied into the leather - he could undo them with just his mouth if he had to. He was safe.