Um, this was probably nothing more than "asked him to take the trash out." Otto is an angsty teen who starts out seeing the world as terribly unfair because he wants to be a fisherman and his father wants him to carry on the family tradition in the shaman-business.
Obviously Nate is the authority here but I didn't read abuse into the sequence, certainly nothing near the level of the future spouse.
On a side note I'm guessing that Otto is mostly or completely out of the picture by the time Sara gets married, I can't see him standing for that.