This dog is not sure of the child and the noises. Notice at first how he looks at the woman sitting then glances back to the baby. Watch as the dog backs up and away from the excited child. Then moves to another location while the woman tickles the baby the dog vocalizes and continues to behave in an uncertain way. The posture similar to a dog investigating a small unfamiliar animal. The nippling and "tickling" this dog is doing is not safe. He is aroused and responding to the continued screaming and motion of the child. This EASILY could turn into a dangerous situation. Dogs Never should be allowed this type of activity with a child. Very very dangerous. Perhaps this dog did not cross the line but....it is not safe to allow such interaction.