This article focuses on the interactions between Disco Bear and every main character he has interacted with.
Because of his self obsession, he usually spends most of his time alone even in public areas. Outside of his relationships with female characters, he gets along with most of the male characters in the show with several exceptions including Mime and Handy.
He has never directly interacted with Cuddles. He subscribed to Cuddles' YouTube channel in YouTube 101: Subscriptions, but Cuddles most likely won't return his friendship because of Disco Bear's fake date with Giggles. However, they were both firefighters in Who's to Flame? and seemed to have no conflicts with each other.
Just like Petunia, Disco Bear is an enemy of Giggles. Unlike Petunia, however, Giggles seemed to like Disco Bear when first meeting him in Stayin' Alive, quickly taking a terrible turn as she gets killed.
Just like Giggles, Disco Bear is an enemy of Petunia, more so than Giggles. Strangely enough, she was shown on a date with him in Blind Date, despite disliking him, even regretting doing so. However, she does seem concerned with him when he gets a heart attack in Change Of Heart and even calling the hospital for him.
It can be easily assumed they're both enemies, as seen in Easy Comb, Easy Go.
Disco Bear and Sniffles were shown getting along as firefighters in Who's to Flame?. On a negative note however, Disco Bear pushed Sniffles aside in order to use the latter's cotton candy machine in Easy Comb, Easy Go.
There closest interaction is in A Vicious Cycle. Disco Bear looks at Cub with displeasment when he is being scolded by Pop for riding his trike in front of the TV. Cub also looks at Disco Bear's splattered head with confusion as he doesn't realize he's actually dead.
Despite being a female character, Disco Bear doesn't really hold Flaky on a high pedestal when it comes to flirting. The only time where he did so is when Flaky made the first move in Ski Ya, Wouldn't Wanna Be Ya!. There are some episodes that imply they are friends, in Class Act, both characters can be seen holding hands together around the burning fire. He is also friends with her in See What Develops, winking at her when they shake hands, while Flaky is seen smiling and has no problem working with him. There are some instances when Disco Bear acts like Flaky isn't around as seen in Rink Hijinks and Ski Ya, Wouldn't Wanna Be Ya!.
Disco Bear and The Mole have a very neutral relationship. The Mole cuts off all of Disco Bear's hair in Easy Comb, Easy Go, but Disco Bear went to him for help again at the end of the episode. They were also partners in Who's to Flame?, doing fine until The Mole unknowingly set Disco Bear aflame.
Disco Bear and Russell are shown to be friends. They ride a roller coaster together in The Wrong Side of the Tracks.
It's unknown if Disco Bear actually sees the duo as enemies. In Sea What I Found, Lifty and Shifty steal his submarine and kill him in the process, but Disco Bear doesn't know it's them. He also makes a friendly deal with them in Easy Comb, Easy Go, which is also the last time Disco Bear is seen with them.
Disco Bear most likely hates Flippy (or at least his other side). He was horrified and killed by him in Double Whammy Part I. He also chases Fliqpy down as a police officer in A Vicious Cycle. While he has interacted with Fliqpy, he has yet to interact with Flippy in person.
Disco Bear is shown to be a fan of Splendid as seen in Wrath of Con, as he was one of the few characters in line waiting to get an autograph from him.