Date night for Sheldon and Amy was going just fine on 'The Big Bang Theory' until Burt joined and Amy discovered he knew a little bit more about her than she would have liked. Turns out Burt knew that Sheldon and Amy only have sex about once a year and that other than that along with the entire University.
It turned out the cause was Sheldon who may suffer from TMI syndrome and a bad case of No Filter. Maybe because Sheldon's kiss and tell confessions involved more tell and less kiss, he didn't see what the big deal was about people knowing about their sex life, since, after all, they barely had one.
But Sheldon came around and realized Amy's anger made sense. True to nature, he tackled the problem with scientific gusto. By mapping basic topics of conversation into a chart called "Zones of Privacy" he was able to approach secrets in whole a new way.