Just get back 'on it' bro. Lead her on. Best bet is telling your best mate to help you out and tell her on msn or something oh yeah 'player3' thinks we should hook up lmfao.. That's how i did it in highschool.
I think you're kind of teasing her AND using another girl to make her jealous.
A similar thing happened to me, it's best not to ignore it though. Just speak to her normally, but don't get as close as you did before.
Dude that really sucks on the first part.
But I must tell you something and i'm glad you did do it.
Once you find out that your just a 'friend'... that means she put you on the block list for bf's.
So stop flirting immediately.
Yes, she is obviously jealous.
Cause girls say that they don't have interest in you but sometimes they really do.