ok so what I'm about to post will make me sound like a complete d*ck which I won't deny.

background: I'm 22, she's 21, when I first met her, I was nice/genuine, just my regular self, asked her out and she denied and her exact words were I was "too nice"
i decided to try an experiment which would alter my personality for this one person

what I usually do with girls I like is treat them nice, be honest, take them out, etc but I've yet to enter a relationship from that.
so for my 'experiment' I just decided to be a completely d*ck to this girl whom we have a mutual friend.

in no particular order this is what I did:
1) text her inappropriate things (mostly about sex)
2) told her to come out to new york from philly and I didn't even show up
3) ignore her texts or respond the next day
4) confessed feelings I don't have
5) make fun of her friends, family, and her in a MEAN way
6) lied to her over and over
7) and many more
...i basically just treated her like sh*t, something that's out of character for me

the result? she's practically throwing herself at me now, she texts me/calls me constantly, talking about our 'future' and how she wants to cuddle, make out, lose her virginity to me...

I need to let her down easy, and since I've never had a girl like me like this before, I need advice on how to do it.
and secondly...it'd be nice if people chimed in on why females, particularly the younger ones respond to the bubble gum bit so well. (Without bringing up the nice guy vs bad boy argument, I know the ins and outs of that discussion)
i'll answer a few questions that you guys have asked

first off, i'm a virgin myself
i dont plan on taking her virginity
i didnt actually think this was going to work
i know what i did was terrible, but curiosity got the best of me
i never had feelings for her, i thought she was pretty and nice so i asked her out to which she declined, and feelings never developed
i am thinkin of ending the experiment as a 'dick' and then just cut her out completely

this honestly makes me sad that girls would fall for this character ive created instead of someone that is honest and genuine with them...