WHY GUYS ALWAYS WANT TO HAVE SEX FIRST THING IN THE MORNING:
You may have noticed men like to get it on first thing in the morning, and science has an explanation why. It turns out a man's testosterone levels are the highest they'll be all day in the morning. This makes him more energetic, focused, sociable, aggressive, competitive and quick to react. It also means him more prone to anger, and gets his libido going. By the middle of the day, his testostertone level has gone down and leveled off, making him better suited for working with others. By the evening his testosterone level has dropped so much that he's likely to act more nurturing and agreeable. (Elite Daily)