Hearing about Lonnie again just reminds me of how Will's disappearance exposed the cracks in the Byers family.
First up, we have Jonathan and Joyce yelling at each other in the streets. Jonathan brings up how Joyce is leaving him to deal with things as usual. He's picked a parent and he so desperately needs to believe that he picked the right one, but Joyce makes that difficult. Jonathan is constantly trying to pep talk and pacify to stop things from going off the rails, but unfortunately that means the person most likely to lose it is also him.
Also he's a child. He shouldn't have to worry about all this.
To make things worse, Joyce reunites with Lonnie when Jonathan stops supporting her the way she needs.
Is this something that has happened before? Does Lonnie come and go when things fall apart? The way Jonathan and Joyce talk about him to Hopper (separately I might add) makes me believe they really don't want Lonnie figuring out what's going on so he can wheedle his way back in.
But he does! And he gets into Jonathan to behave, this time picking Joyce's side when he was badmouthing her to Jonathan before. And Jonathan can't even be mad at Joyce because she does have mental health issues, and he can't get mad at Lonnie because he doesn't want to make things any worse so...
But you can tell why Jonathan didn't believe him when he said he wanted to see him more. Why he's trying very carefully to warn Will about him. Lonnie pits them against each other so that he always comes out on top - this is why Jonathan has trust issues. With both of them. Joyce shuts down, Lonnie swoops back in...it's not great.
I imagine Lonnie tells everyone about it whenever this happens.
And then of course we have Joyce throwing Lonnie out when she realizes she's fallen for his nonsense again. But she's also alone and struggling, at her most rock bottom with no idea what to do next. No money, no support, home in tatters, mental health in shreds, both sons gone, judged by the entire town. It's a cycle. I feel tired for her.
There's a lot of tension in the house with everyone. Seeing Joyce parent Will in season 2 makes it easy to gloss over all this, but the Byers also had way more support. Bob was a fun presence that lent their home a bit of levity, Hopper was dropping by to check on them, Will was getting some kind of professional care, and having a small child there gives them a bit of hope and joy.
We don't know yet if we'll learn anything new about their family history in season 5, but just...the little we did get to see was already pretty bad.