Otou-san no Kodane de Haramasete!
Original title: お義父さんの子種で孕ませて!
Suddenly, the protagonist has to live together with his son and daughter-in law who were recently married.
However, the bride his son brought home was someone, the protagonist had met while particpating in compensated dating before.
Protagonist had divorced from his wife over difference in child rearing policies, 10 years ago.
Few years ago, out of loneliness from being single, he used a dating website to meet people.
He had relationships with various women, but one of them was a high school girl, who is now the wife his son brought home.
Though the protagonist had compicated emotions about this but seeing his daughter-in law had no dishonest intentions and purely loved his son, he approved of them living in his house.
Like this one day, when protagonist was maturbating to an AV out of frustration, he was noticed by the bride.
Then the wife said "Are you accumulating a lot? If you don't mind, do you want me to help you with my hands?" and then...