no no no!
Dont ask her "Are you officially with that guy?". That's a sin!
Apply your DJ charms and skills and let her see that you're better than him without even mentioning him!
Use C+F, neg-hits (if shes h-h-h-hot!), some light kino, and keep the convo aimed at her and what she does etc! Stay happy and confident and cut off the conversation first. Then wait for her to come over to you next time!
Then if all goes well, ask her out or something or ask her for her number (YOU: Listen ive to go now, can i get your number? or something,ike that). And THEN youll know if she has a bf or not!
Anyone else care to share your knowledge?