Rachel decided that her best option was to come up with a plan, and hit her sister, hopefully without her noticing until it was far too late.
Later that night Stacy returned from hanging out with her friends, one thing led to another and it was late, and she was slightly drunk, she sat on the couch and turned on the TV to watch a movie until her head cleared enough to feel like getting ready for bed. About halfway through the movie her sister came down and wanted to watch with her, she thought nothing of it, only slightly surprised her sister would want to hang out with her, she had been teasing her a little much recently. Stacy didn't really mean to go so far all the time, but that is what siblings often do. Rachel was being particularly affectionate tonight, or maybe she was just afraid of the scary movie that was currently playing, but she was latched to Stacy's arm. She didn't think much of it other than her sister felt like she was a little more heavy than usual, she brushed it off as being more tired than she realized though. A few minutes later she got up to get a soda and offered Rachel one, as she was standing she felt as if she had been working out all day long, absolutely drained of energy, maybe she was getting sick.
(back with Rachel) So far her plan had worked wonders, it did not seem that Stacy had noticed that her toned athletic muscles she got from countless hours in the gym had been drained. Rachel planned to do this first so that if her sister was to notice it would be too late and she would be able to overpower her and go with plan B of draining as much as possible as fast as she could, with her sister's back turned she took the opportunity to lift her shirt slightly and peek at the abs she now had, she was no slouch to start with but now she had years of work added and looked as if she had trained for the Olympics, she also had some nice defined biceps at this point and her sister would not likely be able to fight back if it came to that, though the size difference could make them about equal perhaps. Now it was perhaps time to move on to step 2 and hit her where it hurt, it was time to humiliate her as much as possible and enjoy this revenge plan.