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.
Disco Bear is blissfully in love with Giggles as he often flirts with her, even going as far to attempt kissing her in Aw, Shucks!. His love for Giggles may be obsessive as he somehow has a cutout of her in YouTube 101: Subscriptions and even pretends to go on a date with it.
The only time Disco Bear didn't flirt with Giggles was offscreen in See What Develops, when Giggles bought groceries from a supermarket he works at.
Disco Bear is friends with Lumpy. He donated money to him (though in a rather demeaning nature) in Ipso Fatso, thinking he was a beggar. Disco Bear wishes for a giant disco ball from him in As You Wish. He is also Lumpy's partner in A Vicious Cycle and they later enjoy chips and beer at Pop's house.
Just like Giggles, Disco Bear is blissfully in love with Petunia as he often flirts with her. He somehow managed to get Petunia on a date with him in Blind Date, even attempting to kiss her which only results in being pepper/skunk sprayed in the eyes.
It can be easily assumed they're both enemies, as seen in Easy Comb, Easy Go.
Their only negative experience together is in Easy Comb, Easy Go, when Nutty eats his "hair". However, they're shown to be friends in See What Develops as they opened a supermarket together, and sat next to each other on a roller coaster in Double Whammy Part I.
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.
Disco Bear became friends with Pop, when he invited him and Lumpy to drink beer and eat chips in A Vicious Cycle.
There closest interaction is in A Vicious Cycle. Disco Bear looks at Cub with displeasement when he is being scolded by Pop for riding his trike in front of the TV.
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 and Nutty open a supermarket together in See What Develops, winking at her when they shake hands.
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. In general, they are shown to be rather on neutral terms with each other.
Disco Bear, like most characters, is afraid of Fliqpy. He was horrified and killed by him in Double Whammy Part I. He ran away from a swimming competition after Fliqpy murders the audience in By The Seat Of Your Pants. 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.