In the dim light, siblings Thanh and Phan, their bodies close, feel the heat building. Thanh's eyes flicker to Phan's crotch, where a bulge tents his pants. Phan, noticing, smirks. "You're not the only one affected," he whispers. Thanh bites her lip, her gaze lingering on his thickness. She reaches out, her hand hovering, before Phan takes it, guiding it to his length. He groans softly as Thanh strokes him through his pants, their eyes locked in a dance of lust and taboo.