Looking for an Incest Clip (full description)

I'm trying to identify a film clip I saw years ago but can't locate. The scene unfolds as follows:

- A father wishes to be intimate with his wife, but she's too tired.
- She enters her stepdaughter's room, wakes her, and brings her to the father.
- They engage in sex.

I recall the stepdaughter's pubic hair was styled in a V or W shape, possibly linked to the actress's name, though I'm uncertain now.

I associate Mario Salieri with directing, but I'm not confident it's his work. The movie is at least 20 years old.

There might be a scene where the stepdaughter masturbates the father's friend and mixes the semen into the father's coffee, but I'm not entirely sure it's from the same film.

Any leads would be greatly appreciated!