Wow... okay, so I read the entire thing... sounds like a sticky situation...
Thing is, I somewhat get you... I, myself, am crushing BIG TIME on a friend of mine. I told her, and she doesn't see me like that. Which sucks cause everyday I see her, every time we talk, I start to like her more. She knows almost everything, I've told her how I feel and what I think. But you know, you can't force someone to like you like that...
Anyways, idk the situation with you and your partner, but if you feel this strongly for someone and its been for a while... I say tell the person. Trust me, I've been in situations where im like I wish I would've told you how I felt. Cause then you're left wondering what if, what could've been. And its so amazing that my friend hasn't been weird about it or anything. I mean, I did get confused because it felt like she was still leading me on after she told me she doesn't see me like that, and I talked to her about it. And she had said that things were gonna change, cause we flirt a lot and the way I act with her I don't act with anyone else, and the way she acts with me she doesn't act with anyone else. I guess we just have this thing, a good friendship? Idk, I don't understand it. But I had told her that I didn't want things to change, and that I was sorry for everything. For gaining feelings for her, for thinking she liked me back, and for feeling lead on even after she told me she didn't like me. So idk, some ppl can make it weird. Some ppl will change things. Some ppl may be cool, like my friend, and stay the same even if they don't feel for you. And some ppl may feel the same back. Maybe you should come out to her first, if you already haven't. Then tell her about your feelings. I sometimes feel like a freak because of the way I feel about my friend, but I try so hard not to make it seem creepy lol.
So yeah, I think you should let your feelings out and straight out tell her. Cause my friend swears she didn't know and didn't see it, even though all our friends were telling her I liked her, she didn't believe it or choose to see it until I told her. So you never know what someones thinking, or what they see or know, unless you ask/tell.
Don't be left wondering what if, but you know her and can predict her reaction. Just try to make sure she doesn't get weirded out or tries to change things for the bad, you know.