(RAMBLING PROLOGUE) i've lived in hk a long time now and while i've had girlfriends here, and a few one-night stands, i've never had a FB. not here, anyway. had lots of wgs, some who sort of became FBs cause a few would really insist on not taking my money as long as i showed them a good time (nice restaurants/bars/clubs, that sort of shit). but never a real FB, a girl who isn't a WG.
recently i met a girl who just might be a potential FB. very pretty, maybe 4/5, hot bod, 5/5 (from what i can make out while she's dressed in her tight blouses and short skirts

). working class (big plus, i'm sick of posh birds -- no offence, but they just bore me) and her english is excellent (even bigger plus) and she has a boyfriend. BUT she won't stop flirting with me. nothing sexual in conversations, but i keep telling her how pretty she is and she says i'm good looking (which i find surprising. i'm not ugly, but i'm no andy lau). she'll let me hold her hand, put my arm around her waist and pull her in close for a loooong time.

and it hasn't happened but she says she'd love to have dinner with me. and her bf won't mind.
so, great, pretty sure she's somehow interested. i could just treat her like a girlfriend, but i don't want one. i figure she's got a boyfriend who can take care of her emotional needs most of the time, i just want to play with her IF it's consensual that's the arrangement.
(QUESTION HERE) -----> so after that long prologue, the question is, can anyone give me advice on how to go about it? how do i even ask her if she wants to be a FB? do i just seduce her then afterwards make clear this is a no-commitment type of thing? or should we settle that before, which makes more sense, logically, but seems would be very awkward. i figure my best chances of getting her in bed is to do so in the heat of the moment, but i'm afraid after that some deeper emotional attachment may develop.
i know, i know, i'm an amateur compared to all you pros, especially hunter, that's why i'm asking for advice. just ignore this thread if you have no time for it.
thanks
--clueless in central