sounds like your def in the friend zone. i'm just wondering why you want to keep it online if you all go out, and hang? Wouldn't you want some more face time? maybe use okc to playfully setup your next hang out with her? you've done dinner, and drinking. maybe do something active next time, and then poach a jacuzzi somewhere with a 6 pack or a bottle? i'll personally take any excuse to get a girl into a bikini. if that means crushing out an enourmous hike and poaching a jacuzzi, that usually ends really well with movies, take out and sweatpants. it's alot more personal time than a bar scene. i make sure to keep only one blanket in by the tv so you can have an excuse to snuggle up. the poach is an "adventure" to most people, and about the most harmless trouble you could get into. i've only ever been booted once, and we STILL laugh about it to this day! "really?? sorry man, i was just trying to show this pretty lady a romantic time. common girl, back to the trailer and the kiddie pool."
talking about sex in the jacuzzi is usually a pretty easy subject to bring up. (or on the hike too) i think it's good she asked about fantasy. it's different than my sister like girlfriends asking me about the male g-spot. "you asked me about fantasies once. you ever had a jacuzzi (outdoor) fantasy?" dont say it in a way like you want to give it to her, say it like you're talking about the weather. most girls i know think jacuzzi sex is either gross or lame. haven't ever found one that loves it, but you can take it from there. maybe, MAYBE a "have you ever hooked up with a coworker"?? idk i'd have to think that through... but personally, workplace dating has ALWAYS ended bad for me.
anyway, i'm far from an expert with my advice, but hopefully a "pro" will stop in and give you some thoughts.