Zach was almost squirming in pleasure when he felt the nails digging in. His breathing pattern was short with many irregularities. It was so hard to try to...not to, Zach was just so...his hips continued to rock up against Colin's even more than before. It was instinctual, and Zach felt a bit empty, strangely completely empty. Not just...no cock, but no fingers or anything. He kept making noises, failing with words the closer he got.