Sorry about the late response. Since she's Disney and they would have known each other as t(w)eens, he was a little nerd, like his Disney counterpart, mostly a weeaboo and obviously weeb), that sort of kid that no one wanted to hang around at school. He was bullied before getting the role of a lifetime. Thank gosh for tutors and he graduated by the time he was 14 to focus more of his career. After the show ended, he had trouble getting some roles and kind of fizzled out, going to school with a minor role or two thrown in. Growing up in the spotlight kind of changed him, made him care less about what people thought of him and became more of himself and doing what he wants. There was a point in his life where he almost retired from acting, but his girlfriend at the time convinced him to do Riverdale and things kind of spiraled from there and now he has the same fanbase, just more grown up.
And because I kind of want to shake things up, I'm thinking that his brother wasn't his twin, which would cause a huge shakeup once the shows had ended. Blow some minds. He's older by at the very least ten months. I'm just playing on the fact that you could tell the difference between the two twins when they were on the show.