We were played with by our older brother-in-law. I felt his big cock stimulating the inside of my mouth, growing larger and larger. My sister enjoyed the sensation, gently yet boldly stuffing his vulgar part into her cheeks. The sight was a mix of mature allure and pure emotion, evoking a strangely bittersweet feeling. Our relationship with our older brother-in-law wasn't just about desire—it was a special moment born from a deep bond.