FIL is worth at least £1.5 million, most likely more. He has 8 properties (that I know of), a mixture of offices, shops and flats that he rents out. All with no mortgage (he is too old now for a mortgage). He has several pension incomes and 5 cars. Lives in an 8 bed home.
Me and DH are okay for money, however, FIL's daughter is on minimum wage, lives incredibly frugally, sometimes cannot afford to put the heating on in winter, has not had a holiday in 15 years, and is raising 3 children.
FIL never offers help to any of his kids (we don't need help, but SIL almost certainly does). He does not buy Birthday presents either. Never treats his kids to a meal out. Literally nothing ever.
His new GF however, is showered with gifts and foreign holidays and very expensive meals out. She never pays.
FIL also laughs at SIL's lack of car and affordability of things.
No family fall outs. No-one ever challenges him. We are all friendly, so no underlying reason for any of this.
I literally cannot fathom how his brain must work. I can't imagine not helping my children if I was him.