I cannot tell you how much I loved Spock saying "Attend, Captain" to Jim. That was just all kinds of hot. And this:

It stung a little and Jim hissed, remembering the look on Spock’s face when Jim came and remembering that Spock had yanked Jim’s head up by the hair so that he could watch Jim’s face as he lost it. Fuck that should have been a clue.

You just made my day with this. Nicely done.