[Momojiru Teien (Momokumo)] Book where my school sent me nakadashi homework so I got help from oniichan [Nash]

When a schoolgirl's latest homework assignment demands creampie practice, her big brother steps in as tutor - first with a sloppy, apologetic blowjob, then sweat-drenched rounds where she insists he finish inside or she won't get her grade, left dripping and delighted with niichan's seed. The lesson escalates when a bald, muscular father takes over, pinning his petite daughter beneath him to demonstrate 'superior sperm,' her flat chest heaving as her womb gets pumped full and she mewls that all she wants to do is mate. A short, feverish family breeding session from Momojiru Teien where sibling help spirals into a father's hands-on education.