Scott goes frolicking in the woods with Allison, Stiles investigates the alpha and Derek gets tortured by Kate. A usual day in Teen Wolf land. Everyone ends feeling pretty shitty.
We can see Stiles investigating the fire. It's his natural curiosity coming out, but I doubt Stiles can read about Derek losing his home and 8 people he probably loved without being a little bit affected. He also learns that it was likely arson, which gives strength to the things Derek has told Scott, the Argents setting the fire.
Stiles's "Do you find me attractive?" question to Danny comes after he was staring at Derek´s body in Magic Bullet. This is why he is scared. Not because Derek is violent, but because Derek makes him feel in a way that scares him.
Derek is pretty much damaged by his past relationship with Kate. That´s why his trusts no one, least of all a human.
Stiles wears a grey-white checked shirt, a grey striped shirt, and a white shirt with different colors. Derek wears grey shirts and later he is once again bare-chested.