Tuấn's curiosity piqued, he watches Em, his younger brother, entranced by a lurid magazine. Em, realizing his brother's gaze, offers a sly smile and begins to stroke his growing bulge. Tuấn, unable to resist the forbidden allure, steps closer. Em unzips, revealing his throbbing cock, and Tuấn, hesitant at first, tentatively wraps his lips around it. Em moans, encouraging Tuấn to take more, his hand guiding his brother's head in a steady rhythm.