So i opened this girl and number-closed she was a 16(I'm 18 and apparently in TX there is a two year limit before it can be considered illegal. she was about five four and with blue eyes that could kill she was a 7(maybe an

. i waited till the next day to txt her and found out she had a bf. I rode out cocky funny and completely ignored it and kept talking. I told her multiple times that we would have to hang out. she agreed but i told her i might not be such a good boy.
She went along with it and i kept going. i rarely brought up her boy friend and its been almost a week since we met. and tonight she decides to tell her boy friend that i was hitting on her. He called and was a total AMOG(if that is the real meaning again im new) He blew up and i hung up.
later that night i got a txt from the 7 that she wanted to hang out. I kept up my game ignoring the boyfriend. she basically said she agreed with cheating on him just not going to let him know.
she then completely changed moods and told me she loved him and to fuck off so i completely just told her she was a slut and fucked up. I am in colorado right now and she is in tx apparently when i get back her bf is going to kick the shit out of me.
now i am six ft even and one hundred and seventy eight pounds.
this guy is five six and one hundred and twenty pounds.
I am nowhere near threatened but i just would like to know what i could have said to reversed what happened. I have no regret of what happened id just like to get better anti boyfriend game. advice would be pretty awesome.