In Take the Plunge, Firey calls Coiny, "so dumb", and then Coiny calls Firey easy to slap. When Firey tells Match that she made a good choice picking him for their team, Coiny responds sarcastically with "Yeah, right. As if."
In Barriers and Pitfalls, Coiny blows a raspberry at Firey, so Firey slaps him really hard. Later, Coiny is stepping on Firey's hand, so Firey slaps him again, harder.
In Sweet Tooth, Firey and Coiny are eyeing each other angrily. Later, Firey teases Coiny for needing an oven, because Firey is his own oven. Shortly afterward, Firey laughs at the sight of Eraser and Pen spending Coiny.
In Puzzling Mysteries, Coiny refers to Firey as a dumb jerk. When his entire team votes for Firey to join, Coiny votes against him, assuming his vote matters more. When Snowball picks Firey for their team, Coiny tells him that he hates Firey, and asks why he did that. Firey walks over, complaining that Coiny is now on his team.
In Cycle of Life, Firey steps on Coiny's foot, intentionally. When the wheel lands on Firey, Coiny says "Oh no." In opposition to Ice Cube's statement, Coiny says that Firey is a slow runner. Firey then calls Coiny dumb and does not thank him. Firey laughs when Coiny is not selected for the team, and then Coiny slaps Firey.
In Insectophobe's Nightmare, Announcer cites Coiny and Firey as an example of people with arch-enemies. When Firey ends up on Coiny's team again, they argue and exchange another slap. In the team picture for Another Name, Firey and Coiny are glaring at each other. During the challenge, Firey and Coiny glare at each other even more, and are frightened when they realize their legs are tied together. They also slap each other later. When Firey exclaims that they're ahead, Coiny tells him to be quiet, causing another argument.
In Crybaby!, Coiny forgot that water is Firey's poison. Also they slap each other. Later, Firey and Coiny are the ones on Another Name who hold the ski poles. During the handstand contest, Coiny laughs at Firey, then they exchange slaps and both fall over, losing.
In Lofty, Coiny insults Firey, and then they slap a lot. When Golf Ball asks why they slap, they call each other jerks. At Cake at Stake, they exchange grrs when they find out that each other are safe. Then they start slapping, to the dismay of Tennis Ball. Before and after climbing the stairs, Firey makes a weird face and shakes his arm at Coiny. While climbing the stairs, they slap each other. Later, Coiny laughs when Firey screams due to his fear of heights. When Coiny slaps Firey, Blocky is waiting with a nail at his destination to pop his balloon.
In A Leg Up in the Race, Firey calls Coiny worthless, and Coiny responds saying he meant priceless. Then Coiny says Firey doesn't have a brain. They argue some more.
In Don't Lose Your Marbles, Firey slaps Tennis Ball because he needs to fill the void of not being able to slap Coiny.
In Half a Loaf Is Better Than None, Firey laughs when Coiny drowns in bread.
In Gardening Hero, Coiny complains that someone as stupid as Firey is still in and he isn't.
In The Glistening, Coiny was going to vote for Firey, but then he decided to, instead, vote for Firey.
In Hurtful!, Firey is appalled to see Leafy, Bubble, and Flower make dirt cakes like Coiny.
In Return of the Hang Glider, Coiny votes for Leafy because he doesn't want to vote for Firey. When Firey wins, Coiny falls over, defeated. At the entrance to Dream Island, Coiny explains to Firey that he's grown closer to him than anyone he's ever known. Firey lets him in. When Firey and Coiny tell Flower to stop, Blocky says that it's the first time the two of them have ever agreed without arguing, he thinks. Firey and Coiny hug.
In Yeah, Who? I Wanna Know, Coiny's favorite screen is spikes falling on Firey. Firey's is spikes falling on Coiny. When Firey attempts to slap Coiny, he switches teams.
In Zeeky Boogy Doog, when Bomby denies Coiny's invitation to join WOAH Bunch, Coiny convinces him to switch by threatening to ignite him with Firey. Later, when Coiny is reminded of Firey's victory in season 1, he shouts "bleh!"
In No More Snow!, Coiny yells at the Firey Speaker Box, calling him stupid, because Firey made him.
In BFDI Is Back, Coiny and Firey exchange friendly banter while attempting to slingshot Coiny to the top of a tree. Notably, Firey accidentally slaps Coiny and apologizes. This is the first time that Firey and Coiny both show a friendship toward each other.
In BFB, It is confirmed that Coiny no longer hates Firey since they both like Loser and are on the same team, also sitting with Snowball. In Four Goes Too Far Coiny slaps Firey after Firey made the conclusion Black Hole has the twinkle, in which Black Hole has no eyes.