A happy dog will roll on their back and expose their belly to you. This is a sign that they are happy and trusting of you. In fact, a dog initiates physical contact, such as bumping up against you, putting their head in your hand or pulling at you is expressing their happiness and their desire to be with you.
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They understand when you are sorry and will lick your hand to accept your apology.
not true in my case... whenever my dog slept with me, i felt more tired because he kept waking me up... i miss those times.