You cannot be his support system because you are emotionally involved. He needs to be involved in a program with other alcoholics who are leading sober lives. Please don't allow him to guilt you into moving in together and most certainly do not buy a house with him. You deserve better and your kids do too. Just take care of yourself and them and allow him to work out his own sobriety. You don't have to give him an elaborate reason for saying no. As has been said here before...No is a complete sentence.