<human>: Can you condense the text into three sentences or less?

I travel for work quite frequently, and there's a girl living in a city I used to visit a lot for work who I'd see from time to time. When I visited, we'd occasionally go out for a drink or dinner or something. I could always tell that she was attracted to me but she always had a boyfriend and I usually had a girlfriend so it was just friendly thing - up until this last time when neither of us did. I ended up spending a couple nights with her.
It was cool - I like her, she's interesting and attractive, but I've since moved much farther away (like 8000 miles away) and won't be heading over her way very often (maybe just once or twice a year.) However, ever since I hooked up with her its gone from someone I see every few months to someone I get a text message from almost every day.
I'm cool with this, except it's starting to become pretty draining. She's always trying to initiate dirty talk, and I only have a small bank of this available at any time - what do I say when she says some slight variation of "I wish you would come over and fuck me" for the 5th time in a week? "Yeah, I'd like that" is pretty boring.
What's more is that it's becoming very apparent that she likes me a lot more than I like her. She'll tell me about how she can't stop thinking about me and this sort of thing. I don't really know what to say - I don't get these "obsession level" thoughts about her, mostly just "yeah she's cool and I'd like to spend time with her when I have a chance." How do I even respond to these messages? I can't truthfully tell her I feel the same way, but I don't want to crush her, either.
By the way, both of us know that an exclusive relationship is not possible. The distance is prohibitive (but even if it wasn't, I'm not sure I'd want to date her anyway - I kinda like our FWB relationship as-is.)
<bot>: How do I respond to (1) lots of sexual messages without it being boring and (2) how do I respond to her messages about how much she likes me when I don't feel as passionate as she does?