Sean was the boyfriend of Jazz Bashara when she was 17 and he was 23. At 23 he was a Bookie with enough cash to cover all his bets, and was saving to buy a table at the Starlite Casino. He had an apartment big enough for two people to live comfortably. During the time they were dating, he, his friends and Jazz smoked some pot (which is extremely illegal as fire is dangerous in Artemis) in Jazz' father's shop and they knocked over some substances and it burnt down.
Jazz then moved in with Sean and the two lived together. They had an open relationship and agreed that they could sleep with other people so long as they didn't do it at Sean's apartment. Sean was sleeping with other girls, some of which were teenagers as young as 14 and 15. People, presumably the girl's family members, formed a moral brigade and beat him up.
Jazz broke up with him, moving out and onto the streets.
What he is doing now is unknown. As he technically didn't break any laws of Artemis he wouldn't have been deported but most people on Artemis don't approve of paedophiles.