He lives in a rundown part of Miami, in Florida and works at a hotel.
During a beach party he meets and falls in love with Emily, the daughter of his employer. They engage in a dance battle but she leaves quickly after that. Sean later serves Emily a drink but she spills it all over her leg. While watching her dancing, he invites her to the next flashmob of his crew. She turns up and is impressed by their show, so she asks Sean to join the group.
He meets Andie West for the first time thanks to Moose, and the three of them form a new crew, the "LMNTRIX", with new and old characters coming form the previous movies to participate in a competition called "The Vortex", that takes place in Las Vegas amongst the best dance crews in the world.
The prize for the winning crew is a three years contract as professional dancers in Las Vegas. Sean is obessioned wiht the idea of winning because he doesn't want to be forced to return to a life where they constantly have to struggle, since being a dancer is not considered a "serious profession", one upon which a stable life can be built.
He and Andie starts bickering as soon as they meet, both being very passionate and competitive. With time they start to bond and open up to each other also about their previous relationships. Sean tells Andie about Emily and explains her that they used to dance together in his crew and then she left him to go on tournee. Andie talked to Sean about Chase and about how it was difficult to mantain a distant relationship, and about how eventually, she and Chase broke up.
The share a dance on the notes of "Every Little Step" while on a carnival in Vegas and almost kiss, but Andie pulls back.
While performing the duo parts of the various dances, they are each other's partner. Sean wants Andie and him to add a spectacular move to their number and tries to convince her to get up on his knees and then hands so he can hoist her up and launch her. She would then have to make a backward flip in mid-air and he'd have to catch her. Andie refuses because she considers it to be too dangerous and explains to him she is afraid of falling since she the last time she did she broke her knee. Sean tries to convince her she can do it but she refuses again and tells him she doesn't necessarily need to win because she's already happy to be back and dance with all her friends. She is disappointed because he only seems to care about winning.
While battling The Mob he once again tries to force her to do the trick in front of everyone, but she angrily refuses and after the dance storms off. He follows her and once again they clash over the fact that the only important thing to him is winning at all costs and that he's willing to disregard her genuine fears and limits.
Sean comes to the realization that while winning would be very important because it would mean they'd all have not money, not glory, but a job, he also understands they all chose this life, chose to be dancers and worked hard to get there. They love what they do and that's what really matters, living in the moment while they're dancing together and savour every second of it. Andie overhears him and is genuinely happy.
In the end, the LMNTRIX and The Mob merge together to dance in the final battle against the Grim Knights. He and Andie also perform their trick, perfectly succeding. Their crew ends up winning the contest and Andie and Sean share a passionate kiss and dance together with all their friends to celebrate.
In Step Up Revolution he had a brief relationship with Emily but later in Step Up:All In it was confirmed that he and Emily later broke up due to Emily's dance tour.
In Step Up: All In, he meets Andie and after a lot of bickerig and clash they fall for each other and at their final dance they share a passionate kiss and end up together.