I know with my own wife adn with virtually every LD spouse that is mentioned on here, that they tend to need a lot of sleep. Many like to use the excuse that they are to tired for sex. This is a strange concept for me, there is NEVER a time where I am to tired for sex. I love sex in the middle of the night. My wife used to initiate by waking me with her mouth. Now of course, like you , sleep is PREFERRED by my wife over me. Very strange indeed!
