Even though she was a year and a half younger than he was, she still pushed him around and told him what to do all the time. And because of Josh's effeminate and weak personality, his mom had given Kelly the right to discipline Josh whenever she was away at work.
Consequently, Kelly lorded her authority over Josh with a heavy hand, making him hand wash her lingerie and do all the chores around the house, even those that had been specifically assigned to her by their mom. And if that weren't bad enough, she insisted he dress in a frilly maid's uniform and heels, just to humiliate the hapless boy.
At the end of the day, Kelly had set aside what she called "inspection time". This was where she went around and checked up on all the jobs she'd given Josh to make sure they were done to her satisfaction. If they weren't, Kelly felt it was her responsibility to see to it that Josh was properly motivated to make sure he'd do better in the future.
Inevitably, this meant no small amount of tears and a very sore bottom.