My current man is my exs older brother.....?

me and my ex broke up cause he wanted to be with his ex. somehow however we remained friends.... bestfriends. beforr we started datin, i went with him to utah and met his older brother, i instantly was attracted to him. but me and the boy came homee and started dating. then wwe broke up about five months ago. so i started talkin to his brother just as friens. and he was going through a divorce so its noy like he was lookin for anythin serious anyways. but we have been talkin all day everyday for the past five months..... and he tells me he loves me and that he wants to marry me. so we told his brother(my ex) and he totally flipped out. what should i do? also, how do i make the distanbce between me and my man easier?