SMS-031 - I got my little sister pregnant... Big brother's dangerous diary

I got my little sister pregnant after we crossed the line. Now, our forbidden daily life begins. From her smooth, hairless pussy to her growing belly, I can't stop myself from having 'health class' with her every day. She's in heat and begging for more. Our little secret is the stretch marks on her belly. 'I love you, big brother. Fill me up inside!'