any advice on how to bring up the question?
Asking out your best friend
One of my best friends didn't "ask" me out, but told me that he wanted to be more than friends. Feelings were not mutual. We aren't best friends anymore. You can possibly lose the type of friendship you have with them, but if you shouldn't deny your feelings which doesn't answer your question. =P Just tell them you want to spend some time together. There are risks though. Good luck.