[Suddenly looks even more awkward, quiet for a long moment]
I'm not so blind as to say that I don't matter to you. We're friends. [Doesn't add 'and brothers' as he normally would, still a little... well.] Just... It's not the same. [They're the family you always wanted, and now you have a chance to have that here. He doesn't fit that, and he never will.]
... Part of me is jealous. [No sense of pretending otherwise, and he did promise before to be more honest about how he's feeling.] Not of him. [Never of him. He couldn't, not when he sees how happy you are - and how lovely he is. He could never blame him for that.] Just... in general.
But we shouldn't -- [mrr] We don't have to talk about it right now. We shouldn't. You should be focusing on them - on being happy with them. I know what this all means to you. You don't have to explain that, either.