Every night, I hear my brother and his wife trying for a baby. One day, I cannot resist peeking into their bedroom and lock eyes with my sister-in-law Eimi, who looks bored by my brother's mechanical sex. That night, she invites me to cum inside her. From then on, whenever she finishes baby-making sex with him, she comes to me demanding my sperm in her womb. If Eimi gets pregnant, will the baby be mine or my brother's?