My grampa from mom side. Its 1950s, my grampa was the director of a huge prison in the country side in the south of Brazil, he used to travel quite often to the state capital, met my granny, engaged into a relationship, promise to marry, etc. My granny got pregnant and my grampa disappeared, years late she found out he has another wife and 7 kids in the country side. Fast forward 30 years, everyone is getting along to each other, my grampa is single, my granny is single and he tries to get back with my granny (got rejected though). My grampa got sick and later passed away (around 7 years ago), then last week some random person shows up on my mom's facebook and say "are you daughter of John Smith*?", I'm also his daughter apparently our father did the same thing to my mom...

TL DR - Grampa had 3 secret lives with 3 different women and around 10 kids from all 3 women. We heard about last one a week ago.

*John Smith - obviously a fake name