I think for the most part, because Felix isn't QUITE as pissed at Juan as he used to be, he's slightly less wary of Cesare by extension. It's still true that his view of Cesare is more than a little colored by the association, but he's begun to separate them a little bit. Cesare still strikes him as the more mature one (and I mean, I guess technically Cesare and Juan are getting to be the same age, except that Felix actually thinks Juan is at least 5 or so years older than he really is. The facial hair is deceptive.) and he does appreciate that. Also, he's clearly intelligent and curious, and Felix really likes that in a person. He actually does not mind talking to him at all.

Likewise, Tiny!Cesare's curiosity is adorable. Not that he would...put it that way. But it's cute.

What is Cesare's favorite thing about Camp?

(Also, I am almost, ALMOST trained to read Cesare's name in my head the Italian way now. Although when I was writing this I realized I was pronouncing it 'Seh-zar-eh')