Unforgivable Mind

This story was inspired by: https://archiveofourown.org/works/30351864/chapters/74822718

(Tony survived the snap and now has a robotic arm, Clint saved Natasha and non of them jumped, Bucky and Peter are really close as well)

When Peter just started getting his life back together after... well, everything that's happened to him and losing his family, Tony brings someone into his life who's dedicated to ruin Peter's life while he's around for the next couple weeks, leaving Peter in absolute misery.

Or

Peter is staying with Tony for a while, while his adoptive Mum goes on a business trip, along with his adopted Mother's son, his older brother, is away for college and Tony decides it's time Harley visited NYC, but the second Harley saw Peter, he hated him. He was jealous Peter got so much attention.

Background story,
Peter's Dad was a little abusive, mostly just bullying him and some occasional hits here and there, but they never really left a mark. When his parents died in the plane crash, he stayed with his Aunt and Uncle.
His Uncle got shot when he was 12 in front of him as you know and when he was 13, his Aunt was also murdered in front of him when someone broke into the Apartment.
Peter went into foster care and he stayed with a very nice couple and their two sons, one about 3 years older(16) and the other being 6 years younger(6).
Turns out the Father hated Peter for some reason and beat him up one time and tried rapping him a while later when he was 14, but got caught and sent away, leaving the Mother to finally decide to adopt Peter.
Peter got his powers about a week later, and just before he turned 15 he met Tony who recruited him. After the vulture incident, his little brother was hit by a car in front of him and his family when they went out.

His brother knows he's Spider-Man also as well, walked in on him like May did after he got his suit back from Mr Stark.