The conflict between Sean and Jimmy arose when Sean returned to Degrassi Community School to repeat grade 7. His former classmate Jimmy, now in grade 8, tried to make things easier for Sean after he got held back another year, however he took it the wrong way and attacked Jimmy constantly. Although they had several confrontations throughout the year, their conflict came to a head when Jimmy's girlfriend Ashley, high on ecstasy, hooked up with Sean during a year-end party at her house which heated up the rivalry even more, fighting for her affections, but they ended up both rejecting her after realizing she lead them on. Afterwards, they both attempted to bury the hatchet and Jimmy offered to invite Sean to his party which he accepted but showed up drunk and stole his parents booze, in which he was outed by Emma, and Jimmy furiously kicked him out for stealing from him. The conflict finally came to an end when Jimmy unlocked Sean's locked door attempting to not get caught by Raditch and accidentally dropping the keys putting himself in danger until Toby covered for Jimmy.
In Eye of the Beholder, Jimmy is unintentionally rude to Sean, who is repeating the 7th grade. At the school dance, Jimmy attempts to invite Sean to the 8th graders-only after party, which angers Sean and attempted to beat him up until Emma asked to dance with him, saving both Jimmy & Sean.
In Basketball Diaries, Sean joins the basketball team, and is envied by Jimmy. He grows afraid of being cut from the team over Sean, and takes drastic measures to look better than him. Jimmy takes his best friend Spinner Mason's Ritalin, even though he doesn't have ADHD. Jimmy's use of Ritalin boosts his game. Jimmy then fouls Sean on purpose and gets cut from the team.In Under Pressure, Sean is stressed out over exams, especially over his media immersion online test, and is convinced that he failed it.The pressure gets to Sean when little comments from Jimmy toss him over the edge, one things leads to another, and Sean and Jimmy are fighting after school, until Emma was shoved by Sean, and Jimmy laughed at him for it.
In Jagged Little Pill, Ashley makes out with Sean in front of Jimmy and then dumps him, telling him everything she thought of their relationship which hurt him deeply.
In When Doves Cry (1), Jimmy refers to Degrassi as a zoo as the school was full due to have merged with the closed down high school. When he saw Sean, he quipped, "Look, there's one of the monkeys now."In Karma Chameleon, word gets around the school that Ashley is going on a date with Sean to the movies. Jimmy, who is beginning to slowly rekindle his relationship with Ashley, confronts Sean in the hallway. He tells Sean that he and Ashley are back together, and warns Sean to stay away from her. Sean says he hasn't heard this, and that he'll ask Ashley about her relationship with Jimmy when he takes her out at the end of the week. Jimmy lunges at Sean, but their scuffle is quickly broken up by Craig Manning.
In Drive, Jimmy does not attend a boys-only get together at Craig's house after learning that Sean will be there.
In Message in a Bottle, Jimmy is holding a party and gets nervous when Sean turns up and begins drinking his parents' alcohol. When Sean breaks a bottle, Jimmy kicks him out.
Season 3In Take On Me, in Saturday detention everything changes. The attendees are Sean, Ellie, Toby, Hazel and Jimmy, and everyone has to reveal why they were there in a game of truth or dare. They are all bonding when Mr. Raditch separates them. However, they all end up regrouping and take a trip through the school, ending up on the rooftop. Later, just as Ellie is getting ready to take a group photo, her tape recorder falls out and it reveals that she was double crossing Sean, which the others are disgusted by. On Monday, all of the attendees are friends except for Ellie.
- Jimmy was a month older than Sean: Jimmy was born in September 1988, while Sean was born in October 1988.
- They both had romantic feelings for Ellie Nash, but only Sean dated her.
- They both kissed Ashley Kerwin, but only Jimmy had a relationship with her.
- Sean used to be friends with Jimmy's close friends Spinner Mason, Craig Manning and Marco Del Rossi.
- They were both originally members of the Class of 2006 but each of them had to repeat a grade: Sean had to repeat Grade 7 from 2001 to 2002 and Jimmy had to repeat Grade 12 from 2006 to 2007. While Sean was expelled in Here Comes Your Man (2), Jimmy graduated with the Class of 2007 in We Built This City.
- Their girlfriends did not approve of them fighting each other.
- They both were involved in the 2004 school shooting and it’s likely that if Jimmy didn't get shot, Sean would have.
- They were both members of the Degrassi Basketball Team and the Degrassi Hockey Team.
- They both made their first appearances in Season 1: Jimmy in Family Politics and Sean in Eye of the Beholder.
- Sean started dating Ellie in Take On Me, the same episode in which Jimmy started dating Hazel Aden.
- In Drive, Sean sarcastically referred to Jimmy as Spinner's girlfriend.