This one is a bit convoluted for its length, so I'm leaving a summary here for anyone who cares.
MC transfer to a new city where he enter in relations with a family consisting on a recently divorced mother and her daughter. He starts having sex with the mother, but one day the daugther (which by the way has a boyfriend, but doesn't seem to care at all) joins him in the bath and a bit jealous request the same treatment.
Our MC was happily enjoying his new oyakodon life, when something happens some days after. While having sex with the daugther, the mother is apparently about to be raped by a guy. But, when he's about to intervene, the daughter tells him that his mother likes this kind of rough play and usually brings men to do that. By the way, she doesn't fail to notice the excitement of the MC ("cuckold perk adquired!")
Time passes, and while the daughter is having sex again with the MC she tells him the story of how some days ago she was forced by a teacher at her school, who caught her in the middle of a play with her boyfriend. Like mother like daughter, she not only enjoyed being taken in front of the boyfriend, but uses that to tease the MC (some 4D NTR chess going here).
Finally, after dealing with some remorsement about the situation, the MC decides that it could be worse and rolls with his new peculiar way of life. So...happy ending, I guess?