They sleep with you.
We’ve all dog owners wake up with a puppy paw in our back or doggie-breath in our face. Dogs in the wild sleep as a pack which is a sign of being loyal. Moreover, when a dog lives with or is good friends with another dog, they want to sleep together too – but only if they are allowed by the other pup. That means that if your dog sleeps with you is because he consideres you as a good friend.