Funny enough, I think there is a relationship arc, and that's between Spike and Rarity. Would Spike be considered a main character or side character? There have been some hints that Rarity is going to have to let down Spike, but he might be able to make one with Sweetie Belle. Would the Cutie Mark Crusaders be considered main characters or side characters.
Lauren Faust did say that she wanted to keep romance between side characters. Apart from Spike/Rarity, she seems to have stuck to it. Of course, now that she has left MLP: FIM, I wonder if they'll stick to what she said, or if they'll get into it?
Oh, Equestria, we stand on guard for thee!
*readies tranquilizer in case another incident occurs*
@Tigger: Whether that goes anywhere is anyone's guess.
Yeah, Spike is more or less a main character. I just wish he got a focus episode that was less about "he's a dragon" and more about his role in the group.
I don't think Rarity ever seriously entertained the idea of reciprocating. All that happened in Secret of My Excess was that she let him know "I know how you feel, and I don't dislike you for it". I doubt that she really has any romantic feelings for him. She probably just finds it cute more than anything else.
Yeah I don't think Spike and Rarity will ever seriously be an item.
Tealove is best pony.
Ask The Mane Six
How about Spike and Sweetie Belle, out of curiosity?
Hey everypony, back from yardwork -plops down on the sofa, exhausted- Freaking fireants >_<
"Ponies are antidepressants." -edvedd
Next time I do the lawn, I need to wear shoes that are closed-toed, today was like the third time straight I got bit by fireants during yardwork.
"Ponies are antidepressants." -edvedd