My elder son

How nice that he does not feel compelled to 'smile'. Not doing so does not detract from this image and, to be certain, just might add some introspection to the mix. For those who would posit that he is 'sad', perhaps the lack of frivolity might be saner than one is predisposed to think as so. Not everything in life is a joke.

But do not think that seriousness is a necessity; all that I am saying is that it is not a prerequisite for personality. - David Lyga

@David Lyga Hi! Ignacio is a serious boy but also a happy boy. He doesn't like to pose but he knows how much I love him and how much I like photography ... so he poses as himself ;-)
I agree with you. You have remind me of a poem os a spanish poet of the 60s:

Que la vida iba en serio
uno lo empieza a comprender más tarde
-como todos los jóvenes, yo vine
a llevarme la vida por delante.
(Gil de Biedma)

Cheers