[Well, yes, the general atmosphere between them is nothing like it was on their first (real) encounter and all animosities had long since subsided. Still--]

I know, but nobody else in the team specializes in the butterfly stroke. This used to be Rin-san's place, after all...

[He's still getting his mind around that idea-- that his spot wasn't his alone, but something to be shared with Rin on some level. And while Rei, himself, doesn't mind it, he's not too sure Rin feels the same way. Albeit a friendly one, it's still a form of rivalry, isn't it?]

Besides, if I'm to be instructed by Rin-san, it will only be a matter of time until I inevitably surpass him-- and even if he makes that irritating face again, I will not concede defeat!

[He means the crying face, by the way. Not that he actually thinks Rin would cry over that, but it's all part of his tsundere charade.]