Vertical 9:16 social media video, modern bright gym interior with mirrors and exercise balls in b...

Vertical 9:16 social media video, modern bright gym interior with mirrors and exercise balls in background, exactly like the reference image. A miniature athletic young woman with long dark hair is sitting comfortably on the back of a very muscular man who is holding a difficult plank/push-up position on the grey gym mat, hands on the floor, body tense, veins visible, face showing effort. The woman looks playful and flirtatious, smiling, she turns her head slightly toward the camera and says in a cute teasing voice "No pain, no gain~". Suddenly a bright magical pink-white "LVL UP" game UI effect flashes above her head with sparkles. She begins to magically grow much taller and much heavier while still sitting on his back. At first her bare feet dangle freely in the air, not reaching the floor. She looks surprised but delighted, eyes wide, pleasant shock on her face. As the growth continues, her body stretches out smoothly: her spine and torso elongate noticeably, her legs lengthen dramatically, and her buttocks and lower body visibly increase in size and mass. Her buttocks grow larger and fuller, adding significant weight that presses down on the man. She retains all the new larger proportions completely — the enlarged buttocks and stretched body stay at their new scale without shrinking back. The growth becomes very dramatic and noticeable: she becomes significantly larger and heavier than him, her head and shoulders tower well above him. The man underneath starts to struggle more, his arms shaking violently, then his plank completely collapses and he is gently but firmly squashed flat onto the mat under her huge new size. In the end she is much taller and much bigger than the man (clearly towers over him), still sitting on him playfully, looking amazed and amused at her new size. He looks up in total disbelief and shock. Smooth cinematic camera, slow push-in during the strong transformation, soft warm gym lighting with subtle magical glow, realistic physics on clothing and hair, dynamic motion, humorous fantasy-comedy tone, high detail, natural anatomy, no erotic framing, focus on dramatic magical growth, detailed scale change (especially buttocks enlargement and body stretching) and funny reactions.