Hopefully the hotelroom wasn't too expensive
But seriously, its hard to say what you did wrong with this little information. In general, it's something small you did or said, or a vibe you gave which made her feel not comfortable, uneasy and not safe. On the other hand, she might just have changed her mind.
In any case, i don't know what you have been discussing on fb and SPAM, but how well did you get to know her? Did you went further then pleasant small talk? did you dig under the surface and tried to figure out who she is? A lot of women are ok with just sex for because of the sex, but usually its something they dont plan. When they want to get it of, it usually needs to be something that just 'happened'. If it would be planned, sex without 'getting to know each other', you know, just sex for the sake of sex, would make them feel slutty. They would wonder what you would think about them after it happens. Will you look down on her, will you still respect her? That sort of stuff. I don't know what it is you talked about, you might as wel have digged deeper, but I am just saying.
What does strike me as odd is that many guys in your situation just do what you did: its like you hit that wall of what-the-hell-is-happening and you freeze out. It strikes me that so many of you just try again and not try to figure out what is going on. Why didn't you ask her what is the matter? why didn't you try to understand (well, honestly, its probably because you were horny as fuck
)? But still, talk about it! Its your job to make her feel safe when she needs to feel safe. The first 15 minutes, what did you do? She watched tv (i wouldn't have let her) and she fluff talked, but what did you do? In your particular situation, somehting must have been off for her to be reacting like that. Perhaps your mind was thinking to much about fucking her that you didn't notice her mood? This is somehting you should have been able to pick up. If her mood feels a bit off, talk to her, make her feel comfortable. Dont let her watch the tele, take her close, talk and caress her gently. At first in a non sexual way, because, you know, something is off. In such a situation, take it slowly and amp it up when time passes by. Never try to force or push, she will shut down.
I dont know if I made a bit of sense here but I 'll try to summerize a bit and add some organized points:
1) Something happened and make her feel uneasy and/or unsafe. Perhaps you acted differently in person then on facebook/SPAM.
2) this leads us to the second point: how well did you dig under the surface and got to know her? If I want friends with benefits, I make sure we have met in person, I know her quite well (by asking a lot of questions and test her a bit. I need to know who she is if she I am going into a sexual friends relationship with this woman) and only then I state what I want, when I know I want to.
3)how well do you pick up vibes and how well do you adapt to them?
If you have more questions, shoot. I know I might sound a bit confusing
cheers and good luck!