継母！！！私たちがやっていることは間違っていません。パパに言わないと何もバレないから、

It became convenient to have sex in the middle of the living room, with your own stepfather's wife (Stepmother), right after your afternoon bath, and even knowing that your stepfather is at home. The boy asks if that isn't wrong, she replies that no one will know if he doesn't tell her.