Why can't I choose astrology for others

[Saphira]

As I said in the title I get to choose astrology or not at the start of the game. As each character joins I have been offered the choice for Soleil once and not for the two guys. On my third playthrough now and chose astrology for both girls but as the guys joined I wasn't offered the option for either of them. Anyone else had this issue? I'd just like to play with astrology for the guys to see what a difference it makes to the game.

[Indinera]

You are asked, but... indirectly

[littlebro]

EDIT
Changed my mind about what I was going to say, and there's no delete post button.