Yeoman Basha wrote:
For me, it has nothing to do with what may or may not technically be forbidden about Spock and T'Pring's betrothal. It is all about CHARACTER -- more specifically, character consistency. The Spock I saw in TOS would never in a million years have kicked T'Pring to the curb or just blatantly disregarded what was obviously a very serious Vulcan commitment.
Consider this: Dorothy C Fontana was the overseer of most of TOS Vulcanology during the making of TOS. In 1989, she wrote a ST novel called "Vulcan's Glory", set in the Pike era and she has Spock (pre-"Amok Time") in a romantic connection with a Vulcan crewmember, T'Pris.
Before he gets to know T'Pris...
From the Memory Beta synopsis:
"After coming to an agreement with his father, Spock goes to visit T’Pring, where she expresses her own dissatisfaction with their arrangement. Only after Spock agrees to make a formal announcement of their marriage and pay a bride price to her family for the duration of their 'engagement' is T’Pring satisfied (along with her secret lover, Stonn)."
If it's okay with DC Fontana, who are we to argue?