Today, I was lounging around the house, full of sexual desire. Then, I felt someone looking at me. 'Huh?' I thought, and looked at my sister's face, and she was gulping down her saliva and looking at my crotch. '???' I thought, and looked at my crotch, and the tip of my sloppy dick was completely visible through my pants!!! 'Oh, so my sister was looking at this!' I realized, and half-jokingly asked, "Why don't you touch it, sis?" She opened her eyes wide and seemed drawn to it, touching and sucking my dick, and even putting it inside her pussy, which surprised me a little, but from there I let my sister do what she wanted.