Rainbow Dash and Rarity are just, uh, showcasing an aspect of friendship called "banter", the playful and friendly exchange of teasing remarks. [laughs nervously] It's all in good fun.
You see, if you didn't know that Sir Fluffingsworth von Radishfield wears only silk, double-breasted waistcoats, you'd never deduce that he, in fact, was the culprit!
[sighs] I shouldn't have said that. Or made fun of the other stuff you like to do. Some of it's actually sort of neat. [whispers] Don't tell anyone I said that.
I... owe you an apology, too. Buckball may not be my thing, but it's something you enjoy. And you're very good at it. I never should've treated your interests like they were worth less than mine.
(to Twilight) Oh, no, no, no! We're not going through that again! Remember how that all worked out when you weren't honest with Celestia about her actin' ability? (Horse Play)
Pinkie, we all support you, but we're afraid you're just not good at the yovidaphone, and none of us want you to waste your time on something you can't do well.