I'm a college student living alone, and on my days off, I usually stay home eating convenience store bento. One day, the doorbell rang. When I answered, it was Mayu from the next apartment, who had brought over homemade food and some drinks. As we chatted and drank together, I found myself drawn to her cleavage. Did she notice my lustful thoughts? She suddenly climbed on top of me, straddling me in cowgirl position, swaying her big tits and grinding her hips. I couldn't control myself anymore and came uncontrollably into her warm panties.