Little background info:
Cute girl, 7/10, is a best friend of one of my male best friends (friendzoned). The three of us got very drunk a couple weekends ago and she and I ended having sex. My friend disapproved and I felt pretty guilty but I like the girl and she obviously liked me so we cautiously continued communicating. Since then, she has been very flirtatious, asked me to hang out a couple times, told me I'm cute for various reasons, continuously tweets romantic I-really-like-somebody messages, texts me a lot, etc. I've built very solid rapport (we have a ton of inside jokes and common interests and we joke around sexually pretty often).
So I hang out with her two days ago (she asked me this time, so she's asked me to hang out once more than I've asked her so far for a total of 3 hangouts) and it seems to go okay. Being very concerned about not having my friend's blessing, I kept our interactions short of kissing even though I was getting a million IOIs. So the furthest we go is lying in her bed (she's in a dorm and has roommates so no opportunity for hanky panky) resting against each other, playing with each other's hair, playfully touching each other's faces, she calls me cute, etc. I tell her that the whole secrecy aspect of our hanging out is uncomfortable to which she agrees, and that I will clear it up with my friend the next day, to which she also responds positively. She texts me after I get home that "I really love lying in bed and talking to you and good luck with your guys' talk".
I talk to my bro about it, get his okay, and I figure everything is golden. Unfortunately I've run into a hiccup. So our most recent exchange has gone like this:
[talking about our busy schedules today]
Her: Aw man, I bet you're really tired. Well at least tomorrow you can rest to heart's content [shitload of iphone emoji smilies] And shit, I got a D on my last anthro midterm
Me: Hahaha you always crack me up with those iphone smilies. You getting all excited [when we hung out] explaining them to me was way too cute. And don't even sweat it, a D is totally recoverable. I got a D on my first chem midterm last quarter and I pulled an A in the class so I'm sure you could pull the same comeback. Also, let's finally figure out a time to teach you guitar! [she'd been asking me to teach for a few weeks] How's your long weekend looking?
Her: Blehh, I'm not too worried I just thought I'd done better on it. Oh that's right it's a 4 day weekend!!! Oh you know, the usual, lots of getting high and booze <3
Me: Excellent, then how about we set aside some time on Saturday around 4 to get real musical? And right on, nothin worse than dwelling on a test score during a long break.
Her: Haha yeah you're right. How's your studying coming along?
So yeah, she very blatantly and uncharacteristically ignored the invitation to hang out. I don't think I was too flirtatious as I've definitely been a lot more flirty in past communications with her, so I can't imagine that weirded her out. Where'd I go wrong with this? I've already f-closed her so I figured this wouldn't be difficult, especially since I've gotten my friend's blessing.
And what should I do next? Should I neg her out for selectively ignoring a once-in-a-lifetime chance to learn from her friendly neighborhood guitar master? Or should I freeze her out?
Thanks a lot, guys.