When my five-year-old came home raving about something he did with his “other dad,” I laughed—until I realized he wasn’t pretending. And when I discovered my sister Lily was part of it, my world shook.Lily had always been my rock — showing up at 2 a.m. with soup, singing lullabies I’d forgotten, loving my son Eli as if he were her own. Weekend visits with her had become our routine.But that day, when Eli said, “My other dad taught me to whistle,” my heart stopped. His real father, Trent, had left before Eli was born. He didn’t even know my son existed… or so I thought.I followed Lily the next weekend, desperate for answers. At the park, I saw them: Lily, Eli, and a man I instantly recognized. Trent.