He does this stuff when he knows the cameras have to be on him. Truly bizarre. From Tyler Durden at zerohedge.com:
The president of the United States has once again surrendered to his unsettling impulses toward children — weirdly mouthing a little girl in Finland.
The latest in Joe Biden’s long line of cringe-inducing behavior toward female children came as Biden mingled with US embassy employees in Helsinki, before he boarded Air Force One.

In video of the incident, a woman is seen holding a very little girl who’s perhaps one or two years old. Biden shuffles up, and proceeds to open his open mouth wide against the girl’s shoulder before vigorously opening and closing his jaw at least a dozen times.
As she understandably scowls at him in disgust, Biden scowls back for a few seconds — before closing in for his signature juvenile-hair-sniff, only to be denied as his tiny victim squirms away.
Words can only do so much…this one has to be seen to be believed:
Don’t it make ya prouder than sh1t?
Forward!
Si se puede!