What does it mean when he calls you his girl?

Anonymous
Guy I'm kind of seeing called me his girl. He hasn't asked me out officially but is this a way for him to ask me to be his girlfriend?

ALSO: I didn't want to get all serious so was my "flirty" reply good or weird?

Him: "that's my girl :) "

Me: "Lol who says I'm your girl? ;) "

Him: "Me"

Me: "haha if you say so ;P "

Updates
+1 y
He didn't reply after my last text so I'm kind of freaking out that I said something wrong. He hasn't asked me out officially yet but he's been telling his brothers and friends and coworkers that I'm his girlfriend that's why I said "who says I'm your girl?"
What does it mean when he calls you his girl?
3 Opinion