seasider
"Unfortunately it's quite common. He will take what he wants with no regard for others . It's quite embarrassing.."
I'm so very sorry you are living with this. It may be no comfort but, as people are saying, it isn't that uncommon as far as my experience has taught me. I have closely known several men and one woman like it.
Once I took lunch to my friend who was quite badly ill in bed. I left the food to warm and the salad on the work top and went to see her upstairs in bed. I came down and her Clergyman husband was there. I had bought two avocados to share on the salad between the three of us. One had gone. I asked if he had seen it. No he said. I said, did he eat it? No he said, angrily with bits od mushy green on his teeth. I said I would cut the remaining one in two and share it between his wife and me as I knew he had eaten all of the other one. He was raging with anger, his fists were clenched and shaking. He never forgave me and did some very terrible things indeed to me later on.
I shared a room with the woman on a holiday so she would have company because she wanted to be there with her DD and SIL. Even when I begged her to leave me a towel in the morning of the last day, I awoke to find she had used all three bath towels which were soaking wet. She would put all her café and restaurant spending on the room number and at the end she said we should split it in two. I had used it about twice for a cup of coffee. The men I experienced were the same. On a holiday which was meant for me to rest because of my fibromyalgia, I used to have to get dressed without a shower and use the public loo before getting to breakfast because he hogged the bathroom, and I had to do any errands needed for him.
Selfish people are not uncommon. Unreasonable behaviour is the same as with telling lies. We, who would never do such things, naturally do try and find reasons like is he on the Autistic spectrum for the behaviour.
But Autistic people do not behave quite like this - I have studied Autism. If you think about how people who are greedy and selfish and do not consider others operate, you will say they just think of themselves. That is the central point. Their lives, to them, are about getting what they want, not thinking about others. Other people are just there to serve them.
I was being treated so badly by a selfish man that it was affecting my health. He did the things Opalsusanna1 describes and many more. He changed what he had said and made "rules" all the time like "Never, ever, say to me 'I will think about it'" I hadn't said this but he kept stabbing me on my shoulder and shouting it in my face in a pub at lunch.
I sought help from my Team Leader, a Psychiatrist with whom I had worked before retirement on a research project into Autism. He asked if he may send my descriptions of all the things this man did and said to me to a colleague who, he said, "is an expert in this condition and has done an enormous amount of research. He is retired now but works for a charity who help the Victims of these people." The result was that Autistic Spectrum was definitely not the reason. It was something quite different. It was more threatening and less likely to change or respond to help.
The selfish people I know get worse with age. If you are really unhappy now, I would suggest you think about how to get away. Life is short. We don't need to spend our precious last years giving them up to the self-centred egoists who do not value us but abuse us, who cannot love us since they only think of themselves. Your life will only get worse as you, with all the aches and pains of old-age, have to pander to this self-interested person.
If, however, his selfish acts are not so bad and you can cope with them and in other ways he is kind and thoughtful, is considerate towards you, supports you emotionally and is good company, then just accept his imperfections and enjoy the good things.
I wish you everything that is good in your life and most of all happiness.