This is the son that Mama Bushart lost, I believe. He was a stillbirth.
Kristie is 40 years old, but looks horrific thanks to a life of drug abuse and redneck poverty bullshit. JJ has cheated on her several times, including once when he randomly ran off to Florida for two weeks. JJ is a violent, tweaker piece of shit. Kristie is hysterical, dramatic, and kind of a bitch, but I feel bad for her. She has history of super abusive relationships and she seemed to try to convince herself, that JJ didn't smack her, so the fact she was kicked out of various homes, lost a lot of her friends over him, and had a lot of her property stolen wasn't abuse. He was mooching and stealing from someone who already had very little, which seems extra cruel to me. She has already moved in with some dude, but fuck JJ. This new dude at least seems to have a house with power, a fat stack of DVDs, and is at least nice to her on Facebook.
Kristie and Kim have always hated one another. Before Dalton came along, Kim dated/"married"/got fake knocked up by Kristies son (Who also dated Sammie for a while.) JJ and Dalton got into bullshit over Kim at various points before it kind of settled into what it was, with them all pretending to play nice every once and a while for Aiden. I don't think JJ would have some anything with Kim and Dalton, because JJ isn't gay. Dalton, on the other hand, has an insanely bizzare past of cross dressing and having various white men popping up to claim they'd fucked him. Dude is a huge fag.