Marika Sarah Prochazkova in nude scene from 4Some which was released in 2012. She shows us her tits and ass including full frontal nudity in sex scene.
Also Viktorie Cermakova naked in 4Some . We can see sex scene with her. So Viktorie Cermakova is not shy and she demonstrating her ass, boobs and even full frontal nudity.
Actors in the beginning scene are Hynek Cermák and Viktorie Cermakova, who are brother and sister in real life. "I talked to the director before filming about the fact that he should rather cast me and my brother in the role of the tired couple, so that I don't have to play the passion with my brother," Viktorie said. For his part, Hynek said he was not reluctant to play his own sister's husband: "I don't mind immorality, so I didn't hesitate." But he said he was not very comfortable with the bed scenes with his own sister. "I didn't play anything... but the love scenes with my own sister... that was probably the most difficult thing I've ever done as an actor," he said.(IMDb)