There's nothing wrong with the naked body and if your brother wants to see porn, I highly doubt his first thought will be to use Poser.  If he has access to the internet, he'll find a way to get his fix.

Give the kid a chance to use his creativity with Poser without worrying about naked bodies.  If you stop and think about it a moment, naked bodies do not equal porn.  Da Vinci painted Leda & the Swan, Michelangelo painted numerous nudes... the nude body does not equate sex or porn.  It's great that you're thinking of the best for your brother, but maybe overthinking just a bit, lol.

 

Vive Bene.  Spesso L'Amore.  Di Risata Molto.
Live Well.  Love Often.  Laugh Much.