His sister Lisa.

Matt turned to see his sister Lisa standing in the stairwell. Thinking she might scream he quickly said. “It’s me your brother Matt.” His voice came out as a rich baritone and sounded nothing like what it used to.

“You can call yourself whatever you like.” Lisa said moving to get closer to him with a weird look in her eyes.

“No really it’s me. Something at the lab changed the way I look.” He said pointing at his face.

His sister looked at his face and her eyes widened. “Matt? Oh my god you look amazing.” She said her pussy was sopping wet as she looked at her brother and she realized she was still going to try to get him to stick that big dick in her.

Matt did not notice her arm moving till he felt her hand on his dick. Looking at her in shock he asked. “Lisa what are you doing?”

She gave him a naughty look as she sank to her knees in front of him and said. “Helping out my big brother.” He wanted to say something but all he could do was watch as his youngest sister who was barely out of high school put his dick in her mouth. When she started to move her head, he remembered the pen. Looking at it he knew he needed to be careful with what he wrote. He had made himself irresistible to women and it looked like they could not control themselves around him. He did not want to write something that had similar far reaching effects that he could not control.

He was finding it hard to think with his sister doing such a good job sucking his dick. Finally, he had an idea taking the pen he wrote.