Oxford is the son of Sugar Belle and Big Mac. He appears in Far from the Tree. See story below:

https://www.fimfiction.net/bookshelf/1294304/bright-future?order=latest

The opposite of his older brother and really his father, Oxford grew up in a happy home with a whole family and very little to worry about other than his chores working on his father's little family farm. New technology had always been Ox's passion, and as more and more of it was introduced to Equestria over his young life, he fell in love with it. He got his cutiemark shortly after Mac bought the first family computer. Ox explored programming with an old version of python and eventually became a software developer. He doesn't actually need glasses to see, but uses them for their blue light protection. He doesn't go out much or have many friends. Instead, most of his communication is done online. He's actually fairly close with his cousins and immediate family, just digitally.