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 at the lower centre, and both of his arms and hands reaching up into frame from the bottom. Only <Subject 1> touches the woman's breasts.
<Subject 2> is the WOMAN from the source image, lying on her back beneath him: long straight black hair with blunt fringe spread over the white pillow, large bare breasts fully exposed, a small dark tattoo above her right breast, black lace garter belt and black lace-topped thigh-high stockings. She keeps this same face, hair, body and outfit for the entire clip. <Subject 2> never touches her own breasts at any moment.

A POV shot looking down the length of <Subject 2>'s body on a white bed. The same white bedding, white pillow, dark wooden headboard and soft even indoor light, unchanged. <Subject 1>'s erect penis grows from his own pelvis and stays attached to his body the whole time; <Subject 2>'s body has no penis of any kind.

The motion runs for the whole clip and both actions happen at the same time. <Subject 1> brings both hands up onto <Subject 2>'s breasts and kneads them slowly and continuously, his fingers sinking into the soft flesh and releasing, over and over, the breasts squashing and springing back with each squeeze. At the same time <Subject 2> reaches down with her right hand, closes it around <Subject 1>'s shaft, and strokes it up and down at a slow steady rhythm, her hand travelling from the base to the glans and back, again and again without stopping.

Throughout the clip <Subject 2> looks straight up into the camera with a bright playful smile, her eyes crinkling, cheeks flushed, clearly enjoying herself and teasing him. Her expression stays cute and cheerful the whole time and never turns pained or blank. Her right hand keeps stroking and his two hands keep kneading; neither pair of hands stops or swaps places.

<d>[Korean] 오빠 이거 완전 딱딱해졌잖아</d>
<d>[Korean] 가슴 그렇게 만지면 나 이상해져</d>
<d>[Korean] 손으로 다 빼줄게 참지 마</d>

Avoid: the woman touching her own breasts, the man's hands leaving her breasts, the woman's hand stopping, the two people swapping roles, an angry or pained or blank expression, a penis growing out of the woman's body, the penis entering her vagina, the camera moving, any change to her hairstyle, tattoo, stockings or body shape, any third person entering frame, and any extra or deformed limbs.