Sister's boyfriend moved himself into my mums house years ago.
He would treat my other siblings and I with utter contempt and never talk to us. We would try and engage him and it was so uncomfortable. He would sit in silence eat dinner and leave the table even at christmas without saying a word. One christmas not giving a crap that we saw,he sold something illegal from the front.
Funnily enough whenever there was a sniff of money or that he could take advantage he suddenly found his voicebox. The brass neck is actually astonishing.
He is now in my opinion taking advantage of my mother who is a heavy drinker. He is trying to buy her house from her for 100s of thousands below market value and then comparing it with houses that are not even comparable and have so many less bedrooms which are on for a lot more than he is offering.
What would you do?