The bolded statement makes sense to me. When he was dating his gf I believe he tried some weird things that scared off these girls. With his past growing up with a mother who ships him off to boarding school (it also mentioned in the book that holidays such as Christmas and Thanksgiving were spent at school) It makes me feel that he did not have a close and loving mother as many of us do. Together with his sadistic sexual needs and the hatred towards his mother (Im guessing from his cold past) he had a hate on for woman that was buried deep inside him. He went for a few years after his break up until the time he met and married his wife, his needs and hatred would have been festering inside him. We do not know when or for how long his nonexistant sexlife with his wife started (would be interesting to learn this) So again, another woman close to him has turned cold towards him for whatever reason. I wish his family would speak up...we could learn so much more about him.
Here's the timeline for Williams
http://www.cbc.ca/fifth/2010-2011/abovesuspicion/timelinewilliams.html