Only child Clay Jensen got a pseudo-brother in 13 Reasons Why Season 2 when his parents decided to take Justin Foley in for good. That's why Justin lives with Clay on 13 Reasons Why now — the Jensens adopted him. It was a really happy ending to Justin's sad Season 2 storyline, which started with him being homeless and living on the streets.
As has been made clear on the show, Justin never had a good home life. Growing up, his mother had a string of abusive boyfriends living in the house with them. Her most recent, nicknamed Meth Seth, was a particularly bad influence on Justin, who eventually followed in his footsteps and began using drugs. In Season 1, Justin ran away to escape his toxic home life, but he wound up on the streets and abusing heroin. It was this situation that Clay rescued him from in Season 2.
Though Clay only tracked down Justin because he wanted him to testify in the Bakers' trial against the school, he ended up being instrumental to Justin's survival. When Clay brought Justin back to town, he hid him in his room from his parents and helped him detox and start recovery. But while the parents in this show are pretty oblivious, Clay's family did eventually discover Justin had been camping out in their house. However, they were, like, not that mad about it? They reported his return, but let him stay.
However, Justin ended up leaving after overhearing Clay's parents arguing. The raised voices were likely triggering for him, and he seemed to feel responsible for their added stress, so he went back to his mom's. After discovering she was still with Meth Seth, though, Justin realized he couldn't stay there either. Instead, he stole some money from the house and left enough for his mom in case she wanted to escape too. He was on his way out of town until Clay texted him and said he needed him, prompting him to turn back.
That's the thing about Clay and Justin now. They're there for each other. Though they clashed in Season 1, they bonded in Season 2 — you can't go through hiding out in a bedroom and detoxing together without learning to like each other a little bit. Justin was also able to talk Clay down from shooting Bryce and/or himself after Hannah's ghost pushed him into an agitated mental state.
Later, Clay returned the favor. When Bryce was charged with Jessica's rape, Justin was also charged as an accessory for failing to stop and/or report Bryce's actions. Justin was sentenced to six months probation, but couldn't be released from prison until his legal guardian came to collect him. Neither of his parents could be found, so Clay's mom, who is a lawyer, enacted an emergency custody situation that allowed the Jensens to take Justin in. Soon, they all wanted it to become permanent — including Clay, who was initially apprehensive.
"At first I thought it sounded idiotic," Clay told Justin of the adoption plan. "And [my parents] left it up to me seeing as I was the person who brought you into their life in the first place. And maybe it's a good idea."
Justin started crying after realizing that Clay's family wanted to adopt him, and he seemed pretty excited about the idea of having a brother in Clay. It was actually the first thing he mentioned. Unlikely as it was, their relationship became one of the most touching on the show, and in Season 3, you can bet that they'll continue to have each other's backs through everything.
If you or someone you know has been sexually assaulted, call the National Sexual Assault Telephone Hotline at 800-656-HOPE (4673) or visit hotline.rainn.org.
If you or someone you know is seeking help for substance use, call the SAMHSA National Helpline at 1-800-662-HELP(4357).
If you or someone you know are experiencing suicidal thoughts, call 911, or call the National Suicide Prevention Hotline at 1-800-273-8255.