I'm a married healthy man and I have no problem with sex with my wife during the day or at night; however, whenever I've just woken up in the morning and I want to have sex with my wife I can't or seem to have difficulty maintaining my erection during that time. I always tell her I don’t know why my thing down there doesn't like to work in the morning, although I could be really horny at that time...basically my erections are either weak, can't get it up at all, or are difficult to sustain in the first few hours after waking up from my sleep....while during the rest of the day I'm 100 fine.