<human>: Can you provide a brief rundown of the text in within 3 sentences?

So my 26 yo sister (also a single mom) met a 57 yo man at a "function". He's a millionaire. They started "dating" and he just started throwing his money around... taking her on extravagant trips, shopping sprees and giving her cash. We all (the family and close friends) assumed she got a sugar daddy and we weren't really excited about it but she's old enough to make her own decisions and she was having fun and it relieved a lot of her financial pressure so we just kind of kept our disapproval to ourselves. Fast forward a few months and this old man divorces his wife (they were just separated prior apparently), introduces my sister to his kids (who are older than her) and she introduces her 4 yo son to him. All of a sudden they are BF/GF. Who she dates is nobody's concern but hers but we are having a hard time coping with the fact that this guy, who's 2 years younger than our dad, will be a fixture in our lives and my nephew's life. We always wanted my nephew's stepdad (my sister's partner) to be like the father he never had, not some old man with grand kids older than my nephew who's going to die of old age by the time he graduates college. I understand that girls date older men... but 30 years older?!?!?! She's only introduced this guy to a few of her friends and her son, none of us adult family members or family friends BTW. Does anyone have any experience with a similar situation? How do these relationships end up? Any advice on how we as a family can better accept this?
<bot>: My sister is dating a man 30 years older than she is. She introduced him to her 4 yo son. I would like advice on how to accept this new "step dad" figure and any predictions of how this will go.