Papa, Daisuki nara Ecchi Shite! ~Muchi na Musume wa Ecchi no Imi o Shirazu Motomeru~

One day, a young girl named Reika witnesses her parents having sex.
It seemed to her that her mother was bullying her father, so she suggested that they live together.
However, when she found out that her father was only doing it because he loves her, she said that she wanted to do it too.

When her father rejected her, the girl began crying, saying that he won't do it because he doesn't love her.
Frustrated by the girl's crying, the father assumed the pain of penetration will make her give up, so he took action.

The girl started crying after the penetration, but she begged him to continue because she loves him.
However, the pain continued, and the girl tried to run away.

However, the father, having learned about the girl's body, he didn't stop...

[From Elog.tokyo]