McGee heard the crack of his boss's belt against his ass and for a split second wondered why it didn't hurt. Then his brain caught up with what was happening and he felt a wave of pure pain flood through his body. His breath caught in his throat and he suddenly understood why Gibbs had insisted on holding him down. He choked back a sob and blinked frantically against the tears that threatened to spill down his face as the adrenaline rush already generated by his fear of being spanked suddenly spiked in response to the pain.
He was so busy trying to get over the first stroke of the belt that he forgot there would be more. The second lash caught him by surprise. He heard himself gasp, and felt the first tears streaking his cheeks.
The third brought a louder gasp of pain and humiliation. His ass already felt like it was on fire and he wondered, desperately, how many lashes he would have to endure.
His body seemed perversely determined to heighten his senses, as if trying to persuade whatever idiotic brain cells were responsible for movement that it was time to wake up and get some movement happening... away from the current stimulus in the vicinity of his butt, thank you very much. He almost laughed at the realisation that his scientist's mind was even analysing his own spanking, but another blinding stroke of the belt turned it into a choked cry of pain instead.
After the fifth stroke he lost control completely and was keening continuously against the table. He barely noticed each additional lash through the constant haze of pain that consumed him. He was aware of nothing except his burning, throbbing ass and was no longer counting when Gibbs delivered the tenth hard stroke and released his hold on him.
He realised that he was no longer being held down before he realised that the whipping had ended. His newly liberated arm joined the other in cradling his head as he continued to gasp, unable to catch his breath.
He felt Gibbs's hand on his shoulder, squeezing gently. The voice that spoke was unexpectedly kind.
'I know how hard it was for you to face that, Tim. I'm proud of you, son.'
Then the warm pressure was removed and he heard the door shutting quietly. Grateful for privacy, he wrapped his boss's words around himself like a comfortable blanket and let himself cry.