Gee sir, idk
You Tell Me.
Pt. 1
KIRK'S HETEROSEXUALITY IS NEVER STATED!! HIS MAIN CHARACTER ARC IS LITERALLY HIS RELATIONSHIP WITH SPOCK, ESPECIALLY IN THE MOVIES
EMPIRICAL EVIDENCE? IT'S...IT'S EVERYWHERE.
E V E R Y W H E R E
https://www.youtube.com/watch?v=FtQNpJ_8f2w
Spock talking about his mother considering herself fortunate to marry a Vulcan:
Pt. 2 COMING UP
Pt. 2
Oh no! Spock isn't giving me a back rub! Go away pretty woman.
WELL HERE IT IS
Let's not forget that the series DEFINES ROMANTIC LOVE as someone you'd "lie, cheat, steal...sacrifice your career, your reputation" for (Dagger of the Mind); and "... more important than anything? Is he as though he were a part of you?" (Metamorphosis)
AND THEN IN THE SEARCH FOR SPOCK (having already had a dry run in Amok Time) HE DOES THIS FOR