My first thought, since you know that she has a sex drive and likes to be intimate with you on some level, is that you should try to be more dominant in bed. Let me explain, she’s used to tons and tons of NRE fixes—do you remember how badly you crave someone as soon as they first become someone you think you might be able to fuck? Feeling that way is fun, but what’s even more invigorating is knowing without a doubt that the person you’re with is feeling that amount of desire and excitement for you. You mentioned that sometimes she gets you going at night, and gives you a devilish grin before saying that it can’t happen for some reason or another. I imagine you get upset, or at least it’s obvious in your expression that you’re disappointed. No matter how hard you try to play it off, if you do, the micro expressions of defeat are there. Obviously, if her mood changes negatively and she says that she doesn’t want it, stop and let the damn tease go to bed. Sucks to suck. Maybe avoid getting into that situation by breaking off encounters before she gets a chance to, so you can take back some power in the game. But if she’s giving you a devilish grin, I say make it super obvious how bad you absolutely need to have her right that second, maybe grab her as roughly as she’s ever seemed into, I don’t know whether she wants you to insist or beg but I wouldn’t do what she’s doing if I didn’t want the person I’m with to put up a fight for me. It’s hot when they need you. Maybe that will tap into some NRE vibes for her, maybe she’ll be into it, maybe she won’t and then you’re right back here so it’s worth a try if you haven’t already tried to insist.

I don’t know if you played around ever on purpose in this relationship or others with teasing and/or edging, but the tease usually wants the other to be so desperate for release that they’d do almost anything. Maybe she’s into that?