You gotta work on your social etiquette first before thinking about escalating.. You really just weirded her out right away..
A girl just str8 up ditched u mid convo -ouch let that be a lesson for you man.
#1 Thing when approaching any girl is you have to prove to her you're not a weirdo or creep <-- you failed this step
The big mistake alot of amateurs make is they think you need to be overtly sexual right away because alot of idiots/douchebags tell them this.. Problem is alot of guys don't k now how to diffuse her alarm bells first, and then be flirtacious in a suave manner. The way you did it comes off as really weird... I mean seriously you guys were talking about politics or some sht then you started actin like a creep? what a weird segway.
Yes i get that she told you to walk with her ands aid shes flexible.. you started off flirting with her alright, then you started overly pushing a typical idea that alot of amateurs mention "50 shades of grey" like as if every chick fuccs with BD.SM, then she said somethin playful after tryin to tell u not all girls are into that-you took it weirdly serious and personal and basically asked her if she was damaged or some sht or if someone "roughed her up" as a child-- what a turn off lmao