Firstly, no you are not being unreasonable in wanting things to change. I would sit down and explain to him that is it making you feel uncomfortable in your own house and that this is not just a house, but your home together. Don't continually nag him about it, as this may well just make things worse and ruin your relationship. You need to accept that this is what he is like, but at the same time try calmly to get him to understand how this is affecting you. As a compromise, suggest he keeps the things he hoards in one room of the house. You could also suggest you help him sift through the many items and sell what he will agree to get rid of, with a view to the money being used to buy him something he would really like to have or, if there is enough, towards a holiday together. I have great respect for other people's things and how they want to live their lives. But in a partnership, the personalities and characteristics of both people should be given equal importance and equal respect! Just try to do this in a positive, friendly manner while also making your views count! Good luck!