by Lenny & LoSarro – A marathon FMG (Female Muscular Growth) from Lenny. Young man’s secret mail-order shipment of Growth Formula is intercepted by his younger sister who drinks it for herself and subs her chocolate milk drink for him to take thinking it is his formula. Before she even gets back to her bedroom the formula starts working on her. Next day big brother gets a shock at first seeing his now much bigger sis in the bathroom. He figures out why the stuff he had drank did nothing for him. Then sis takes the last two cans of formula and gets even bigger. Her big brother has always been a kind of a pain-in-the-butt to her, but when she see’s a group of big bullies about to pound on him she has another growth spurt and deals with the tough dudes quite roughly. Much more happens like twin girls the brother bullies while babysitting getting some of his re-order of the formula so they can punish her brother for his bad behavior. Meanwhile sis just keeps getting bigger. Brother finally gets some formula to drink, but it is the shrinking antidote that renders him no bigger than his sister’s hand! So sis keeps helping other girls get bigger than any guys who are mistreating them and doing other things that use her big muscular body best while ‘big’ brother is now her mouse-like cheerleader/sun-screen applier! 101 pgs.