[IENF-021] When I was getting sympathy from my sister, a high school girl at an all-girls school, she promised me, 'It's just rubbing,' and let me do the 'sukomo' (a form of sexual play without penetration), but we both felt too good and my penis slipped in effortlessly! 'Eh!? It's inside?' But we couldn't stop and ended up ejaculating inside! 7