Photorealistic live-action cinematography, soft even indoor light, natural skin texture and visible pores, vertical 9:16 frame.

There are exactly two people in this clip and their roles never swap.
<Subject 1> is the MAN, whose eyes the camera is. He is off-screen except for his thighs at the bottom edge of the frame, his erect penis rising from his own pelvis up through the centre of the shot, and his two arms and hands reaching into frame from the bottom. Only <Subject 1> slaps. His erect penis grows from his own body and stays attached to it the whole time.
<Subject 2> is the WOMAN from the source image, kneeling low between his legs and leaning forward over his lap: long straight black hair with a blunt fringe, bare breasts pressed together around his shaft, black lace garter belt and black lace-topped thigh-high stockings, her face lowered to the tip of his penis. She keeps this same face, hair, body and outfit for the entire clip. Her body has no penis of any kind. <Subject 2> never slaps herself and never touches her own breasts with an open palm; her hands stay pressing her breasts together from the outside.

A POV shot from the man's eyes looking down at <Subject 2>. The same beige tatami floor and pale wall, unchanged. The camera is fixed and never moves.

The motion runs for the whole clip and all of it happens at the same time. <Subject 2> squeezes her two breasts together around <Subject 1>'s shaft with a hand on the outside of each breast and slides her chest up and down along it, the soft flesh dragging over the wet shaft, again and again without stopping. At the top of each slide she drops her head and takes the shaft deep into her mouth, all the way down her throat until her lips reach her own breasts, holds it there for a beat with her cheeks hollowed and her eyes watering, then pulls back off it with a wet string of saliva and goes straight back to sliding her breasts. She repeats this rhythm — breasts sliding, then a deep throat, then breasts again — over and over for the whole clip.

Meanwhile <Subject 1> brings one hand up and swats it down onto the side of her squeezed breast with a light open-handed slap, the flesh bouncing and reddening slightly, then does it again on the other breast, slapping her breasts over and over throughout the clip while his shaft stays between them.

Whenever the shaft is in her throat <Subject 2> makes wet muffled humming sounds around it. Whenever it comes out of her mouth she looks straight up into the camera with a bright playful smile, eyes crinkling and watering, cheeks flushed, clearly enjoying herself. Her expression stays cute and cheerful and never turns pained or blank.

<d>[Korean] 읍… 웁… 웁읍…</d>
<d>[Korean] 야 더 깊게 빨아 이 변태야</d>
<d>[Korean] 오빠 때리니까 더 좋잖아</d>
<d>[Korean] 웁… 으읍… 웁…</d>

Avoid: the woman slapping herself, the man's hands leaving her breasts for long, her breasts leaving the shaft, the shaft leaving both her mouth and her breasts at the same time, a penis growing out of the woman's body, a pained or crying or blank expression, the man's face appearing, the two people swapping roles, the camera moving, any change to her hairstyle, stockings or body shape, any third person entering frame, and any extra or deformed limbs.