I am currently playing a 9th lvl celestial blooded sorcer, I just got my wings of hevean ability and am quite excited to fly around and cast spells, My GM told me that he considers flying a "vigorous actvity" and will require me to make Concentration checks to cast while using my Wings ablity.
I have GM'd several lower level games and have not run into this myself,but I feel like this is wrong and I am not sure how to broach the subject to him,
Any advice? either on how to talk to him about it, or if the ruleing he is making is correct or not?
thanks