As we had exams going on, I and my sister had exams at the same time, so we used to leave the house at 8:30 AM and return together by 12:30 PM. This meant that I did not get to fuck my mom every day as usual. I would study hard as I had promised my mom to be the topper in my class which was a condition for her to accept our incest relationship. Whenever I could get a chance, I would try to grope her boobs or ass and push my raging hard 10-inch long and 4-inch thick cock on her ass cheeks or pussy area when my sister and dad were not around. As I mentioned in the earlier parts, I had started to give hormonal injections to my mother and some tablets to try and enhance her breasts to produce milk which was my fantasy. Though her breasts were full and size 36DD earlier, the injections and tablets enhanced her boobs to 38C, but they still did not produce lactation yet.