Is it normal that my best friend's girlfriend is attracted to me?

My story begins in late 2013.

I have a really close friend of mine in the army, who I have known for quite some time now. We bicker and fuss like siblings, but we always support each other through everything.

One summer evening, my boyfriend went out with one of his (now former) friends, and another guy that they both knew. I knew who he was with, and I trusted him. There were two girls that came out with his friend.

The girl I did know, was a girl that used to have a huge crush on my boyfriend, long before I met him, but never acted on anything. The other girl on the other hand, didn't seem to mind all that much. His so-called friend was trying to tempt him into cheating on me. I solely believe he was trying o break us up so he could try to talk to me. Anyways he said "No, I'm good I have a gf" which had been confirmed by the other guy. So, the 2nd chic says to him, "Aw you're a great boyfriend she's lucky."

Here's where it gets twisted. The night after that, she messaged him on FB saying how "fine" he was, and asking if he had any friends that looked like him. He showed me the messages, and I kept it very close in mind. Upon meeting her, my boyfriend introduced her to my best friend to get her off his back. Horrible mistake. So they hit it off. Then things start happening that bother me. One day, when I'm not present, my best friend steps away to go talk to his grandpa. She offers my boyfriend one of her friend's phone number to him, just because she told him she was interested. Note that this "friend" of hers she has had sexual relations with before meeting my best friend. And she's just sitting there waiting for an answer, AFTER she had already met me and kept emphasizing how "pretty" I was, and after telling me to my face he was "fine as hell."

It gets even crazier. As time passes on, her statements start being direct at me. She starts saying things like "I would rape you," "you have a fat ass," "you're sexy and cute," she would always compliment my face as well as my body, and it would be IN FRONT of her boyfriend and Mine! One day she even made an indication that if she had a chance she would screw me. She even went as far as grabbing my ass as I'm walking, and I jumped. Whenever I would wear a dress, I would almost receive the same look a guy would give when he found a girl really attractive. Nobody would say anything either, my friend and bf just gave her this look as if they didn't know what to say. And of course I don't know what to say, because anytime I would try to talk to my friend about he would get Very offended...My bf felt like something was up.
So here it is - Just recently she starts to text me about her stretch marks on her bum. I didn't respond, because I didn't wanna talk about it. So the next day she wishes me luck on an interview, and I say thanks. Trying to diffuse the topic itself I say, "don't worry about it all girls get them" So then, she explains how she doesn't like them and all, and then says she sent me a pic with the winky-tongue emoji. iPhone users YOU KNOW which one I'm talking about.
I hadn't immediately replied because I was cleaning up at the time. And when I finally did, 15 minutes later, I receive a picture of her bum in a g-string. Now, where does it get awkward? The whole "I'm bi" thing has been on and off with her, for one. Number two, if you were specifying stretch marks, then wouldn't you have zoomed in close enough to catch JUST the stretch marks???
Not that I was looking that hard but you couldn't even see what she was talking about.

So I tell my boyfriend, and for a moment he starts flipping out. I kept the messages ONLY to show him (he was out) and did not want to be incriminated. And when I tried telling him I still had the messages it was almost like "Why??" But now that it's deleted I no longer have any "proof" of this. I've already made it clear I'm into guys only, and I'm starting to feel like she may have a thing for me even more. I feel awkward around her, my boyfriend feels awkward around her, and our friends and family get strange vibes from her.
Am I just overreacting? Is this just a bad case of "girls being girls" which I highly doubt, or does she Really have a thing for me?