My Fiance Might Need To Go Back To His Ex

Dear Steve and Shirley, I am an engaged 33 year old female. I don't have any children but my fiance has two children aged 17 and 14. When the children are with us. I'd do anything I can to make them happy. Sometimes they try to be nice to me but most of the time they are very disrespectful. When they don't get their way, they have gone so far as to call me an airhead and stupid to my face.......