Prompt

cowgirl position, wide spread legs M-pose, woman leaning forward aggressively riding man, extremely rapid ultra high-speed tiny vertical hip pistons, micro-strokes with almost zero vertical travel under 0.3cm, hips hammering down hard and fast onto pelvis with only negligible lift, thick hard rigid erect penis constantly fully inserted deep inside vagina, never pulls out even slightly, no upward stretch or deformation of penis at any time, fixed penetration depth, internal sliding motion only, woman's upper body and face completely static and fully visible in frame, forward leaning posture, heavy motion blur on hips and waist only, dynamic lower body action, realistic genital details,