It is ancronym which means, “before anyone else” in simple English it means some who you put above all else it could be a parent or even a best friend but it’s mostly used to describe a boyfriend/girlfriend
This is what embarrassing losers call their significant other for some stupid ass reason. What it really does is make you sound like a brain dead retarded 10 year old that is trying to be cool.
Don't ever usethe term Bae because it's not a word and it makes you seem like you are an idiot punk who just makes up stupid ass words.