I'm trying to find a story I read years ago on the bdsm library site (at least i think it was here as it was long ago i read it).

What I can remember of the story was that it was about a family where the daughter is having trouble with her grades, in particularly studying and doing home work. The family consist of a father, mother, daughter and son. I think the son is the youngest.
The father with the help of the mother build a special chair to help the daughter study.
The chair is a bondage device that the daughter gets strapped into leaving only a hand free that is used to study. It also has an elaborate feature that are able to measure how well the studying is going and that there are no goofing of, that feature were also able to give test. The twist of the chair was that it had a can that whipped the daughter between the legs on her pussy when she was goofing off or got an answer wrong.

I don't remember much of the story more than the chair and that it was about how the parents first developed the chair and then used it on the daughter and how it helped her get her grades up in the end.

I also have a faint recollection that at the end the parents discussed modifying the chair to work on the son too.
It was also rather long. At least more than a dozen pages.

Anyone know what story it is?