disclaimer: this is my personal headcanon and not considered actually canon.
i imagine these two grew up very wealthy, and their parents were likely business owners or something. because they owned businesses and had international meetings and things, they weren't cant around to care for their children. therefore, the twins were mostly raised by nannies. the lack of affection from their parents had a big effect on them. they tended to act out whenever they could and isolated themselves from their peers.
growing up rich and isolated is what caused their arrogant nature. they never had many friends, and consider each other to be their one true friends, because of trust issues stemming from their absent parents (if that wording makes any sense at all lmao).
they got into street dance as a way to rebel against their parents, and fell in love with it. although they won't admit it, they love the community surrounding it, and of course, the attention.
a/n: so i wrote this on my phone during school so +7000 dweeb points for me
uh i've noticed it the only (semi) active dance central book/account left??? that's cool
coming out eventually: angel oneshot & more headcanons