so the only reason im posting this is to see what i could have possibly done wrong so i avoid doing this in the future, it JUST happened and im already starting to game other chicks. here is my whole story:
we are both 17, she lives a good 30 minutes away by car and i dont drive yet.
i was her first kiss, and shes been in america for like 3-4 years. shes usually shy
we met on facebook through a friend of mine, i did all my flirting and connection knowledge inside the private messages we sent back and forth. i got her to give me her number first day we talked after about 2-3 hours of flirty conversation.
in a few days we started talking on the phone.
since the first day i showed intention to meet up wit her, but through difficulties we met up after a month, on our first date i showed her my leader-like personality, such as guiding her through the crowds at the mall, getting her involved in conversation and making her comfortable by being funny and teasing, we end up kissing
i get to see her twice every 2 weeks because i sleep over at a friends house because i used to live in the town she lives in now, and i always advance sexually, i dont turn into the nice guy and stay "alpha"
around the 3rd weekend of meeting up with her she starts acting weird, she admits that she is acting weird , but i still manage to be fun, flirty, and a leader.
throughout our whole relationship i constantly tease her, give her funny nicknames and play around with her a lot playfully, but at the same time i say how sexy she is and touch her sexually.
the next week (this week) shes barely talkin to me lately, i start actin a little nicer and comfort her, she tells me shes not used to this stuff (im like her first kiss and major boyfriend)
yesterday she messaged me on facebook , and said hi like 20 times and put a smiley face, i gave her a flirty response , then told her i cant talk right now cus im busy and that was that.
TODAY, its april fools day so i decide to call her and give her a little jolt by joking about breaking up with her, i build suspense by takin my time in sayin it and pretending like im serious, she says ok without any hint of regret and im like wow that was easy, i tell her bye and we hang up. she then changes her relationship status on facebook to single.
my question is what went wrong, was i too alpha for her (she is really shy, but i also made her experience things she never did before) ? i was trying so hard to not be a nice guy that i dreaded becoming, was i too much of an asshole? i did show that i was joking all those times of teasing, but she didnt have any regret sayin it.
ONE LAST MOST IMPORTANT THING!
she did have a thought that i was cheatin on her, she knows that other girls want me because shes seen girls look at me when we're together. i met her sister on facebook as well a little bit before we first met up, and shes 20. i flirted with her a bit too, and she began to like me. she drove her to our date so i got to meet her.
later on that day we talked on facebook and she said i was better than her boyfriend and a lot of other signals. so my girlfriend might have an idea that i flirted with her sister.
its really important to figure out what went wrong so i dont do it again, because im into girls like this, ones that are shy until u get to know them, so please help

thanks