It goes pretty well for Sebastian, he spends the week at his dad's place and the weekend at his and Lennon's apartment. He set up the spare room in their apartment for himself to sleep in. He invites Heath over almost every night since Sebastian has a hard time sleeping alone. 

It doesn't go quite as well for Lennon, he's been distanced from the most important person in his life and has no idea when he can get close to him again. Lennon ends up reconnecting with his family and spending more time with his younger sisters, which he's happy about, but for him, it still isn't as fulfilling as spending time with Sebastian. 

When they start talking again, two or so weeks into the break. Sebastian offers an option for Lennon; Lennon gets a side partner, someone who can fulfill needs that Sebastian doesn't always have the energy to. At first, Lennon denies the idea, saying it's too complicated. But slowly Sebastian convinces him to at least try it and if it doesn't work out they can figure something else out. Lennon finally agrees and they begin looking for a potential partner.

Sebastian ends up asking if he can have Heath over every weekend, staying overnight, basically living with them during weekends, and Lennon reluctantly agrees, He doesn't hate Heath and he knows how happy he makes Sebastian, though Lennon does worry about how close they're getting and wondering if Sebastian even cares about him anymore.

They aren't fully back to how they were, Sebastian still sleeps in the spare room most nights. But the two of them have been beginning the process of talking it out, figuring out exactly what each of them wants in life, and deciding if it makes sense to stay together.  

About a month and a half after the break began, they come to an agreement that right now and for the foreseeable future (5-10 years) it makes sense to stay together, and even if they don't end up spending the rest of their lives together they still want to be with each other for now and that's what matters.