The Lonely question

maybe I missed something in the later part of the book that should explain it but I was under the impression that Eli hasn't had GFs and that doctor woman was a mistake, etc. so how long must that room been around and for what purposes? why did he have it in the first place equipped with spanking instruments???? at some point I believed he hadn't used it w/anyone else besides Sarah but did he have it set up knowing one day he'd have her in there? unless he had it set up to serve the purpose of torturing her after having her believing she was abducted???

great book btw!