This is creepy and weird and won't help you in the long run - your living a lie. Plus it will be terrible if something happens with that girl and you start seeing her or whatever andshe later finds out that friend isn't your ex. Your over complicating it - whilst thereissometruth behind it just forget all this social status mince.

Just flirt with her and if things go well ask her out for drinks or back to yours to help you improve your French tongue (between her legs obvs)

And make sure if you do ask her out its clear this is a date and not just as friends.