Australians may have a new excuse for infidelity: "sleep sex." That's the diagnosis given to an otherwise respectable Sydney-area woman who snuck out at night to have sex with random strangers while her live-in boyfriend slept at home. "Incredulity is the first staging post for anyone involved in this," admitted Peter Buchanan, the diagnosing physician and a sleep specialist at Royal Prince Alfred Hospital (search). "One has to maintain a healthy degree of skepticism." But, Buchanan told the Sydney Morning Herald, the woman wasn't covering up run-of-the-mill infidelity. She was genuinely unaware of her activities. Even her boyfriend took a...