Theo and Stiles in “Unfinished Business”

Theo

You know who you remind me of?

Stiles

[sighs] Theo, I don't care.

Theo

My sister. She was smarter than everyone, too. And a pain in the ass like you. But she always looked out for me, the same way you look out for Scott. You know, I was the one that found her body? She'd fallen into a creek and broken her leg. They told us she would've been okay if it wasn't one of the coldest nights of the year... If it wasn't for the hypothermia. And when I found her, all I could think was that I should've known. That I should've been looking out for her.

Stiles

...Why are you telling me this?

Theo

I'm telling you because even if you don't trust me, and even if you don't like me, I'm still going to be looking out for you... the way I should have been looking out for her.