A father is sent a video of his daughter who is of legal age having sex. He is surprised to say the least. But he begins to get an itch to have his daughter sexually. He sets out a plan to seduce her, but he will not force her into doing anything she doesn't want to do. Eventually his plans work. He's surprised at how tight his daughter is.
He eventually finds out that his daughter had been a virgin before him. The woman in the video he had seen hadn't been his daughter but just a woman that looked and sounded a lot like her. Now it makes sense on a few differences between the body in the video and his daughter. Things liketan lines, marks on the skin and other things.
His daughter may or may not get impregnated by him.