Four Times Chekov got on McCoy's Nerves and The One time the Doctor wanted him to
It's not been a good night for McCoy, because yet again he's missed his daughters' birthday. Joanna will be eighteen today and this is a time where he should be there more then ever. She's got her prom to look forward to, serious boyfriends, first car, first job, arguments with her mother about her future (he's not sure whether she's told Marie about wanting to join Starfleet. Bright kid wants to be an officer and he's so proud when she says she wants to go into medicine like her dad) There's all these things for Joanna, all these firsts and he isn't going to be there to see them
Which is why he resents it when Chekov comes into his room, a goofy nervous smile on his face, informing the doctor that the Captain has ordered him to join the celebrations. Bones remembers then that it's the Ensigns eighteenth birthday today too, and that the bridge crew have thrown him surprise party- much to the young mans embarrassment- especially when Bones was there to see Kirk playfully clap the ensign on the shoulder and announce –very loudly- to everyone that Chekov can now go out and get himself laid, with an exaggerated wink at an equally embarrassed Sulu. And this only serves to make Bones resent the kid even more, although the feelings are probably exacerbated by the copious amounts of sythehol in his system. He hates the fact that Chekov reminds him so much of Joanna, from his wide-eyes expression, big blue eyes displaying the sort of youthful innocence that he knows will probably fade with time aboard the enterprise, to the naïve grin plastered across the Russians face. It isn't fair he gets to see this kid grow up and not his Joanna
"Sir?" the kid's speaking to him "Sir, ze Keptin asked me to reqvest your presence..."
"Just leave me alone, kid" McCoy says it so quietly that Chekov can't hear what he's saying
"I said, just get out, dammit!" Bones snaps, turning away so he doesn't see the hurt look in Chekov's eyes as the ensign mutters sadly "Aye, sir" and leaves, leaving the doctor to his ghosts