Eyy yo, who wants a buncha sad lore :')
Bc boy howdy, I sure love me some of that. Anyway, ya boy Ben has had a bit of a rough life.

(TW for mental illness, bullying, parental neglect, and shitty coping mechanisms)

Niks (this dumb lil biomecha race i've made) have a huge emphasis on partnership in their culture. And an even bigger one with having a child after you've committed to your partner. Ben's father, Stanley, ended up in a relationship with a much older Nik after he recently became an adult. She bought his affection (she was pretty rich) and Stanley ended up obsessed with her. An obsession that ended when he got pregnant and she hit the road (anyone is capable of getting pregnant regardless of biological sex).
Single parent Niks, especially ones that have had a child before they've committed, are looked down upon by society and are considered sluts and idiots. Stanley ended up homeless after his mistress left him and he had to go back to his parents, who weren't too happy with him showing up with 1. a baby 2. with no partner. The two were very much old fashioned and sticklers to tradition, so they scorned and chided him for what had happened to him. However they allowed him to stay as long as he paid rent for both himself and Ben.
Stanley worked full time at a restaurant to pay the bills. His dad, bless his core, wasn't around as much as he'd like to be. He was always working to make money to keep a roof over Ben's head as well as earn enough money to move out of his parents.
Ben grew up in his grandparents house till he was an adolescent. Till then, he experienced serious neglect and rejection from his grandparents. His dad always spent time with him when he could, but was working most of the time. The neglect ended up creating some serious anxiety for Ben and he stress ate. A lot.
It's usually very hard for Niks to gain weight, as their body has a mechanism that stops them from continual eating. However, there are some that eat so much that they override said mechanism. And thus they cannot stop eating sometimes and they gain weight. Thus, that happened to Ben, who already was structurally on the bigger side, but his overeating enhanced it. It got him made fun of a lot in school and it didn't help his mental health much. He eventually moved out with his dad and they moved into a new house. Stanley had a coworker, who was very kind with some children of her own, who were much younger then Ben. They'd visit from time to time and he'd hang out with him. They were the closest to friends that he got and he eventually ended up wanting to become a teacher because of them. He liked kids and wanted to teach them, despite how badly he had been treated by his classmates.
Ben still stress eats a lot and although he tries to control his splurges, he still ends up consuming a lot when he's stressed or upset. Adrien is trying to help him out of it as well as get him professional help to deal with it, but Ben is pretty resistant about it.