Kyousuke attempts to represent Kirino as her brother, and Kuroneko follows up nicely in support.

(Ore no Imouto ga Konnani Anime-ka na Wake ga Nai)
"There's No Way My Sister is Getting An Anime Adaptation"

There wasn't a whole lot of interaction between Kousaka siblings this episode, but the way that Kyousuke continues to go out on a limb for Kirino even without her knowing about it never ceases to amaze me. In fact, it's gotten to the point that Kuroneko even wishes she had an older brother like him, which goes to show that just about everyone's taken notice to his constant sacrifices for her.