I think 3am is the hour you fall in love. When your thinking brain is turned off and the only thing that fills your consciousness is remembering the feel of your bodies folded together; cupping the nape of his neck with your fingers while he slowly strokes the arm you've draped around him as you both slip in and out of sleep.
This is the hour you write love letters in your head, paragraphs of mad devotion that don't even need to make sense, they can just be the brain in love in the middle of the night. When you wake, you won't remember everything you thought and even if you did, you wouldn't tell him. But you will decide this is bliss, and there can never be too much bliss.
(Sent from my phone)