Thanks for the advice guys.
Update:
- I hooked up with a girl that's part of our very close 6-7 friends group - we didn't actually have sex (she was on her period) but we dry humped, kissed, made out for 1 hour or so on Saturday, she left me a HICKEY ON MY NECK.
- I saw the girl (one I want that has a bf) today for first time in 3 days and she saw my hickey - I thought my t-shirt would cover it entirely but it didn't, and she seemed extremely interested. She kept asking me what happened, to tell her who did it, etc.. I didn't and told her I'd tell her some other time, the other chick who I hooked up with was right next to me.
- Got home, got a message from the girl, asking me to tell her what happened. I was playing dumb, not saying very much, nothing at all really. She kept pushing, saying "telllll me", or "who is it???

", "I want to know what happened", but I didn't tell her anything. She then went on to say: "we talk about our professional careers and studies issues so we should also talk about personal issues. Disclosure depends on level of friendship".
-I told her "Believe me, level of friendship is at max with you but don't think disclosure depends on friendship level". She said "I disagree" and then went on to say something about how she thinks I should tell her.
-She asked me if the girl I was with on Saturday was the girl that was ACTUALLY with me and I didn't respond.
Now, what exactly does all this mean? Is she jealous or something? Do "real friends", especially if it's between a boy and girl, behave this way?
Is the fact that I'm not telling her making her jealous or should I tell her if she keeps pushing? She's the girl I'd fall for if she had no bf so don't really know how to deal with this now.