What you're saying reminds me of the riddle from the movie "Tin Cup".Hmm, typically the riddle doesn't specify that they're men and the answer is mother/father/son.
that's just not right.A man has a wife, and they have a son.
The son grows up, and has sex with the mum, producing another child. The man is now the father of the older boy, and is still blood related to his wife's new baby. He thinks that baby is his son, even though it's really his son's son. His weird older son had sex with his pervy mum to produce that younger son.
Now where's my prize?