With Harry, it was because of Norman treating him like a failure as a son and praising Peter, in his face for that matter. The parts with MJ and football were because Peter was slowing losing the nerd status that they both had.
Eddie, I think it began when Peter turned in the photos he took of his fight with the Lizard to the Daily Bugle, and then Connor's fired him (Peter). I can't remember what made Eddie hate toward Peter worsen prior to getting the symbiote though.
It's funny though, I think out all of the Spider-Man shows, and maybe media, that Spectacular showed Peter's job at the Bugle negatively impacting his life the most. He was in a situation of where he needed to make money to help Aunt May at the expense of losing his friends sometimes.