Wow, so lame.
I'm sorry. It sounded before like you guys had strong communication and that whole bracelet present thing was so sweet... I wonder what the heck is happening now??
"Keith tells me the next day that he noticed me leaving but decided not to check on me because he thought I needed space - fair enough, but I would have liked him to since I slipped out when he was asleep. It would have been nice to know I was missed, I guess. Fiona came upstairs, knew I was up there, and didn't come into the room. I didn't realize it was her that was in the bathroom so I didn't go out. Once again, would have been nice of her to check on me to see WHY I wasn't downstairs sleeping (or sleeping at all), but ok then."
Stuff like this speaks to me of needing to feel more comfortable speaking up for your needs. If you go away, of course people are going to assume you want space. For you to want them to know that you in fact want the opposite is to expect your lovers to be mind readers, and trouble lies that way.
Of course, that aside, I would be mightily pissed too in your position
If you love her and want to give her a chance, it's on you to speak up and make it clear that you felt hurt. Revealing a wound and risking a second rejection is terrifying, but brave communication is absolutely necessary in matters of the heart. It may be that something was going on that you just can't guess at that would explain it, like maybe she'd been feeling alienated from Mario for some reason and really needed to be close to him for sleeping purposes... which doesn't explain her not listening to you and not kissing you, but it would at least be interesting to hear what on earth was going on with her that evening.
Or, of course you could just walk away. None of us would blame you, I'm sure. I would imagine though you'll feel more ultimate closure if you at least talk to her about it first.