The less than ideal prompt I used to generate the video examples

positive:
Video of sexual intercourse involving penetration of the pussy. In a detailed, high-resolution CGI style, a young woman is filled with pleasure as she feels the unexpected penetration of a man's body pressing against her. Naked and toned as the man's penis smoothly enters her wide-spread legs. Her mouth is open in pleasure as the man thrusts in and out of her body. Her body rises and falls in harmony with the man's penetration, her breasts bounce gently, her nipples tense. Live2D. Emotionless. The face does not change its expression throughout the video.

negative:
The video is not of a high quality, it has a low resolution. Watermark present in each frame. Strange motion trajectory. Static image. Static video. Camera movement. Blur. Change of frame.