By mid-semester, the online classes were done, and my grades were recorded. My sister - like our cousin - had realized that the easiest way for me to lose control over my balls was to whisper naughty suggestions to me about how my load of forbidden seed was going to put an incest-baby in their belly. On this particular Friday night, I had already cum in her once - doggy style. She had woken me up a couple hours later and wanted another load - arguing that we wouldn't get another chance for several days. I gripped her perfect perky titties in my fists and groaned as her whispered suggestions...