Unusual behavior mix poodle shih tzu

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My year old dog called Marley in honour of Bob Marley (love reggae) has unusual behavior (have 5 other dogs). She kisses or more like smothers the faces of all the other dogs everyday. With the 2 golden huge labradors, she has a love hate relations with them. She annoys them with barks and little nibbles to their face and at the same time kisses them to death (he is a third of the labs size). Can anyone tell me what this behavior means? Where did he get this habit? Thank you.