looking after widowed father inlaw

Sllms Mufti I was married 6 years ago and for the first 2 years we stayed together with my widowed father inlaw. My husband is the only son and he has one sister who lives with her inlaws.Our relationship between myself and my father inlaw began to deteriorate (for various reasons the way he spoke to me, dressing in shorts etc above his knees, domestic matters) At times we would be confrontational as I found it hard to adjust to his ways. I also found out that he does horse betting . My husband was to embarassed to reveal this and my father inlaw likes to put on a facade as if he does nothing. . Anyway, for the past four years we have been living separately and we now have 2 children. we bought our own place where my husband and I are both co-owners .It is a flatlet so there are space constraints .My father inlaw lives alone for the past four years.
I would like to know are we obligated to keep him in our home if he becomes sickly or old as i cannot see myself living under the same roof as him again as our marriage will suffer and i become depressed with all the tension in the house. . If he attains old age can we offer him other forms of support . I am willing to give him food Can you advise what is the shariat from point of view of the son and also of the daughter inlaw ?