Find your tribe in a Sea of Creativity
I'll just say Zach is spending quality time with the brothers' mom, Linda loves Zach because he's cleaner than Martin and Chris.
Linda never saw Zach as a bad child, she simply saw Zach as a child who lacked affection and love, which is why she felt happy when Chris got to work to change Zach.
Poor Chris has to be with Zach 7/27 at Aviva's request because he doesn't trust him. Martin simply didn't want to go with Zach, he felt uncomfortable and Chris gave him the opportunity because now they are partners.
Martin and Koki are partners now but for a short time