Episode 5 of the Step Sister Series: My family physician Dr. Dervla Harper made a house call to read my medical report from a team of neurological experts. The bad news is that the effect of having so much frequent sexual activity with my step sisters has caused my brain to start degenerating. At the same time, they've detected an increase in brain cells in the head of my cock. It's a rare condition that cannot be reversed. I haven't been using my brain very much for anything besides sexual activity, since my step sisters won't let me have the time to do anything else. So my brain is breaking down, just as when you don't exercise your body's muscles. Since my cock is the body part that has mostly been used in the past year, that's where new brain cells have been stimulated to grow. Essentially, my brain is slowly migrating from my head to my cock. Dr. Dervla Harper has an experimental treatment for this. She's going to accelerate the process of brain cell development in my cock by regular, weekly sexual stimulation administered by her. She said since the degeneration process in my brain cannot be stopped, the next best thing is to encourage the growth of new brain cells in the head of my cock since that has already begun. That way I will at least have some cognitive function, but it will be mainly focused on sexual impulses, unfortunately for me. I won't be able to think about much of anything else, but it's better than being stuck in the transition stage that I'm in right now where my brain and my cock are competing for control over me. My doctor's first session involves pressing down then bouncing on my cock with her big, soft, round ass, before grinding on it harder to make me release a big load of cum.