I have a girlfriend I love, but I ended up getting addicted to sex with her sister 'Eimi'. I know it's wrong, but I can't control myself anymore. During the one month my girlfriend is away from home, I forbid myself from masturbating or having sex, all for the sake of going at it non-stop with 'Eimi' and building up so much semen that my balls feel like they're going to burst. Me and 'Eimi', freed from our abstinent lifestyle, went at it from morning till night during the days she was gone, ejaculating inside until we risked pregnancy.
