I have to say, Chapel does not come off well here. She tells everyone else about her acceptance into the Korby fellowship... except Spock? That's kind of disrespectful, because she always had at least a fundamental respect for him and cared for him, and this just doesn't follow her previous motivations. No wonder he ends up going to full Vulcan mode by the time of TOS. The man has done everything he could to be understanding and helpful in the relationship... given space when needed, changing the subject Dak'Rah was going on because it was upsetting Chapel, etc. And you know he would be the first one to say 'go for the fellowship' and not guilt her to stay, because he's a good guy. I don't buy the excuse of the Boimler scene in the turbolift is her way of getting out of his way for his destiny... she was already on the fence of even being in a relationship in the very next episode after "Charades". Spock's line to Stonn in "AMOK TIME" about wanting and having a thing really carries extra weight because of Chapel... she's basically the living embodiment of that sentence.