What is Henry's last name? I would like to assume its LaMontagne, but have we ever been told for sure? (Because its possible its not since they are not married...yet.)

Hi!:)
Well, as we know, they are not married. So, I talk for my country, when the parents are not married, the child get the name of the mother. So I assume, he will have the name of JJ. But, as I do not live in the US, I cannot tell Du for sure.