I almost swooned. I opened my mouth and allowed his tongue inside. A moan escaped my lips as our tongues began to duel. Then I felt his hand on my bre...st ... my tiny but oh so sensitive breast. My knees grew weak as I felt him pushing me toward my bed. When the backs of my knees hit the bed we both fell backward with him on top of me, our lips still together."Sis, I want you," he whispered."Yes," I answered, unable to say more. I felt him pulling down my pants, my underwear included. A moment. "Just for a second," she answered. Chris smiled and positioned the head of his penis between her rapidly swelling lips. He moaned as he felt the soft, blood filled, lips caress the head of his penis. "Oh God Mom," Chris groaned and leaned down to kiss her lips again. Allison placed her hands on her son's hips, holding him back, keeping him for moving downward. "God Mom, just an inch more." Allison's body began to tremble. "No... we can't." Chris pushed down, forcing another inch into his. Terry knew, of course. Ever since learning that if he put his dick in a girl's fuck tube and squirted his sperm in her, she'd get pregnant. The idea thrilled him. All he needed was a girl willing to let him, and the trouble was, the only one he could talk to was his sister.Their parents were both fluent in French, and had been visiting the country for years, so they knew their way around. Terry's dad had a job with computers, and his mother was working long hours in a fashion store. She. What were once a pair of beautiful thin legs, were now fat and ugly . . . at least two times their original size. She grabbed her waist as her stomach began to churn. Her gut began to expand, soon swelling to match the rest of her oversized physique. Then as I gazed at her gorgeous face, I watched a double chin begin to grow . . . her whole face puffing up like a balloon. I was stunned . . . what was once a walking hard-on had somehow turned into a 200-pound pile of obesity in only a matter.