Why would his mom make him break up with me?

my boyfriends mom made him call me yesterday and break up with me for no reason i didnt do anything she says hes not suppose to have girlfreind but he abut to 18 so i dont see y he cant its not fair i have to go through heartbreak just becasie she wants to be mean he was cryen and so was i wish i knew the reason y she made him do this 2me