Need help about a girl i hate?

ok im a boy,and theres dumb,fat girl who i hate,is been mean to me,that dosent means she is beating me(im a boy)cause all she says is shut up(name)id love to insult her 1 day,but i seem so fair,i dont know what to do,(well i still do insult her by fairness because shes always insulting me,i should do the exact same power of insult she does so i do it)i once made her come and kick me(girls!!! lol love to kick)im like"oh,come one,is that the best u can do"she was so mad,because i called her a big fatso(llllllooooooolllllll!!!!)she is,and the point is,why is she so mean to me(the only boy)i dont understand is she racing,or something?i need some reasons of why she hates me,she was normal to me in the beggining of the year but something happened,i need help.(also her sister does the same thing,twin)but i know the reason(all i dont know,is why she does that,im fed up,and dont tell me to tatletale on her,cause i dont want t do it (for a reason)so i desperatley need help,1.tell me some insults