I don't paint dreams or nightmares

Dominic (or Dom -- he doesn't care, either is fine) is quite a bit like Bay, except for that Y chromosome and chunks of his background. Like Bay, he's an artist, sarcastic, and relatively introverted. The main difference in terms of personality is that Dominic grew up in a much less privileged setting than Bay, and thus is less prone to acting like a spoiled brat. However, like her, he can be quite a drama queen at certain times.

Dominic's parents are Regina Vasquez and Angelo Sorrento. He still shares a birthday with Bay Kennish but, because Bay was a girl and he was a boy, they were never switched.

When Dom was three, he caught meningitis and lost most of his hearing in one ear. Angelo couldn't cope with having a sick kid and took off back to Italy soon after, so effectively Dom was raised by his mom and grandmother in the working class neighborhood of East Riverside. He reconnected with his father during his sophomore year of high school, but they don't speak often.

Dominic's hearing loss isn't as severe as Daphne's is in canon, and he's able to make up for most of the deficit with a hearing aid. But he spent some time at Carlton School for the deaf, coming to Fandom after that school closed down in the middle of his junior year.

And the Kennishes? They're out there, raising Toby and Bay-who-could-have-been-Daphne, with no idea how close they came to their younger child being switched at birth.

I'm assuming Dom will remember being friends with Bay's friends, albeit with some differences -- e.g., I don't think they have the same taste in makeout partners. But if you want to work out a more detailed backstory for Dominic to remember about your character, hit me up in the comments.