Their eyes meet, a silent agreement passing between them. The brother tentatively reaches out, cupping his sister's large, round breasts, feeling their weight in his hands. She gasps, her nipples hardening at his touch. He leans in, taking one into his mouth, suckling gently. She moans, her hands tangling in his hair, pressing him closer. Their bodies flush against each other, their breaths coming in short gasps, they lose themselves in the forbidden pleasure of their taboo encounter.