You spot a bathroom a little ways off and decide that's the best place to go. Maybe you just REALLY need to go? You change your heading, gripping your abdomen in pain. Your skin is starting to burn and you're barely able to stand straight with all the pain. Despite all this, thoughts of Erin are at the forefront of your mind and you can't help but undress that recent memory of her. Your mediocre dick strains against your underwear forming a tent in your cheap trousers.
You pick up the pace, hoping that you'll get there soon. People are turning to look at the strange man jogging towards the bathroom, gripping his stomach, and sporting an erection. People share concerned whispers but you pay no heed as the pain worsens.
Finally you get into the men's bathroom, pushing an elderly man out of the way as he was about to enter the last available stall. You slam the door in his face as he makes some grumbled remark about the youth of today.
You drop your trousers and sit on the throne, but you have no urge to go. Your dick still stands at attention. The pain is spreading, the burning sensation covers your whole torso now. It feels like there are insects crawling on your chest. You rip off your shirt and see your body changing. Your skin bubbles and shifts. The truth dawns on you as you see what's changed so far.
By God! You're turning into...