ATTENTION LadieS!!!!!!!!! QUESTION????????

I went dated this girl for a over, and a year stopped 5 mos. ago. The last time I actually spoke to her was a lil over 2 mos. ago. I wanna call her and ask her out to lunch, but am afraid to get turned down cause she has a boyfriend right now. I usually dont do this, but on top of her bestfriend tellin me that her current boyfriend's insecurity is pissin her off,....I miss her also too. My question is: How can I make the conversation go well enough to ask her out to lunch?? Where could I take her that's more "fun" than just seein each other?? Any other tips would be great too!!???