Why does this boy always be so mean to me?

it all started in 6th grd i sat right behind him and always use to annoy him (thats becuz i use to like him). Then in 7th grade he liked ME and i H8ted him for bin so mean to me in 6th grade, and in 8th i didnt c him, now in 9th hes in 1 of my cles and always talkin bad about me in front of my face, so far he did it about 3 times and i ignore him he was talking to this girl (shes my friend but he didnt know it then) and this guy ( hes his best friend, and i also known him for somtime, i dont lik him either) they was sittin together talkin about me and my friend was bing quiet. she neverd told me wat he said, and his best friend wasnt sayin much bout me. Plus she didnt kno i over heard him talkin about me. i needed help on a math problem i asked this aid to help me and when i found out what i was doin wrong i said O..and i heard him say to his best friend "she said o shes sooo stupid" was i bin stupid?! i didnt say it really loud of retarded or anything. wat should i do?!hes an as$