There's no onscreen sexual assault, but the series revolves around a conman who has romantic relationships with his victims, and it's implied that the relationships are sexual. So you could infer offscreen rape by deception.
1x5 At around 28:30 Cheryl v*. Audio. No visual of her face, the camera is behind her, across the room. It's over by 28:50. The rest of the episodes are safe.