How is 20 years oblivious and he finds out that his daughter knows and they all disrespect him, and he goes to jail gets fucked over. Thats revenge? A note?
If you want one where OP/MC does a lot of Hollyweird "revenge" stuff, this will disappoint you. If you're fine with OP/MC, for the most part, simply defending his pride and dignity after finding out and divorcing with maybe setting a house on fire, but realistically having to do the time for that, then you'll be okay with this one.
False paternity is a terrible thing to do, to take a man's chance at having children by lying to him like that. A woman gives birth, she knows she's the mother, a man is left to believe or only hope he is the father.
S2: Gentlemen: NEVER have normal conversations with a wife after you know she spread for another man. It is business conversation with an enemy from that point forward.