. Brother knows sister's graduation is a special time, so he goes to her room to congratulate her. His sister's nerves are getting the best of her, so he decides to relax her with sex. With no one around, he takes out his cock and convinces her to give him a blowjob. She eagerly obliges, and as she licks his penis, he spreads her legs and plunges his big dick into her tight pussy. Nerves evaporate as they make passionate love,- making her graduation night one to remember! (560 characters)