My late father spent a few years in prison for fraud a couple of years before DS1 (26) was born.
I have never told our children this. I didn't see any need. He died when they were 10 and 3. DS1 has sweet childhood memories and DS2 barely any.
I have been divorced from his father for 8 years.
DS1 told me yesterday that my ex told him about my Dad. I simply said that it was not his business to discuss and then explained honestly and frankly about everything. I try not to bad mouth ex to the kids, so I've kept this bottled up. I asked DS1 not to tell DS2.
I don't have any sort of communication with ex any more (a Court Order stated DS2 didn't have to see him any more a few years ago so I have no need to communicate with him). So I will not confront him.
I just feel sad that DS1 now has a different opinion about his Grandad.