Mickey has a bad attitude and sadistic tendencies. Aiden is easily distressed, but secretly likes being toyed with.
They're a a dysfunctional pair with lots of emotional ups and down, but they always makeup by morning.

Some years later, their relationship somehow managed to hold together, and even becoming stronger.
Mick became a little more mature, letting go of a lot of his anger issues, but still enjoys teasing Aiden and seeing him cry.
While Aiden became more confident and beautiful, figuring out how to push Mickey's buttons in all the right ways. Now Mick struggles more so with jealousy over Aiden's other admirers.

Mickey works at an animal shelter specializing in problem dogs. It's part of the reason he simmered down as he got older. He enjoys it because the dogs won't reject him for his 'resting bitch face.'
Aiden works at a cafe/reading lounge. No particular reason for it, he needed a job and he thought it would be easier than something like barista or waiter. Was mostly quiet at work, but became more talkative over time when he figured out the regulars and how to chat them up. It helps to get them ordering more often. One regular even tips well...when Mickey isn't hanging around to give him a menacing glare.
As for hobbies, for Mickey it's either dogs or cars. He hopes to restore a classic vehicle one day.
Working in a reading lounge, you might think Aiden's hobby is reading, but he is actually a horror movie buff. He likes them all, but really enjoys the ones that work in romance subplots.

They met in a public park when they were about pre-teens. Aiden was crying alone on a park bench, being ignored by the other kids and passersby. (Evidently there were no decent adults around.) Mickey saw him crying and came over to make fun of him.
Aiden graciously lapped up the cruel attention from Mickey because he was a neglected child, sorely lacking any sort of attention at home, and was ostracized in his school life as well for being a crybaby.
They continued to meet like this for several weeks as Mickey had nothing better to do from having almost no friends himself either. Other kids often pushed him away because of his anger issues and attitude, but no matter how mean he was Aiden never pushed him away. Eventually they were practically inseparable as close friends, with a cycles of mockings, crying, and makeups. A very strange looking relationship to those around them.

As they got older, Mickey's attention started getting taken by pretty girls, and Aiden just would not stand for this. Mickey's attitude had started to rub off on him, and he became hostile to the women that came around the two. Luckily for Aiden, he had naturally feminine features. A subject of torment from his classmates when they were younger, but now his weapon to keep Mickey for himself. He knew that Mick couldn't resist his tearful eyes, and with some work he'd make sure Mick couldn't resist his other charms either. Mickey enjoyed this newer, fiery, side to Aiden, and found himself drawn further.

At some point after their dating relationship had began, Aiden made the mistake of intentionally invoking Mick's jealousy by openly flirting with another man. He didn't really mean anything by it, he just wanted to get a rise from Mick so they could do their little song and dance of fighting followed by a makeup.
But Mickey gave hardly any response. Just a short glare, and a long, cold-shoulder that lasted several days. It was an agonizing torture for Aiden, and a mistake he wasn't going to make again.