Spirk? What Spirk? What is this 'sexual tension' of which you speak? I don't know what you're talking about. *commence suspicious whistling*
Basically, the point of this is that, when you see Chapel holding Spock's hand or Troi holding Riker's hand while they are injured/resting/whatever, you automatically assume that she loves him and that love may or may not be reciprocated, right? And (don't deny it, you know it's true) if either Spock or Kirk was a girl, this scene would also be read by all as a romantic scene. There just wouldn't be any question about it. So why does the implication behind the scene change when they're both guys? I'll give you a hint: It doesn't. At least not for me. XD
*cackles like a loon* Posters like this are the reason I've decided to watch TOS after all. A few episodes in and I'm actually starting to get used to the horrible CGI and slow pacing. What you get in exchange for it is after all so completely worth it