How Do I Know If My Best Friend Likes Me?

So i guess you can say i've fallen for my straight best friend :/ I know, I know, i'm supposed to avoid straight girls, but I can't get past all of the flirting she does. I've recently told her about my confusion about my sexuality, and she's so supportive. So, she knows that at some time or another, i've been attracted to a girl. Who? She hasn't asked.
She usually flirts with me the most when we are with a group of friends. We always pretend flirt, even when we're alone. We'll be cheesy and stuff, but not for real. But then, we were in the kitchen alone, and she tried to kiss me (not for real, atleast i dont think it was) and i pulled away, but she has done this for a few times) Then later, we were with a bunch of our friends in the car (no adults and everyone had a seat), she started moving around and sat on my lap, and we sort of hugged and she kissed my cheek. Then, theres the casual hand holding. I cant tell if she likes me or not, since she sometimes tells me that she could turn herself if she wanted to, eventhough she knows im bi.