I agree. However it is the Mother (presumably father also) at home who set this rule. So SHE would not want a poker player either.

This business of "I am not comfortable ...with your...." has gone on a bit too far.

I am a vegetarian, could I ask her / you not to eat meat because I don't want such influences either?

See how far this can go.?

On a short flt it is OK to switch activity, but I would also have to be restrained from saying , " Yes m'am, in my home they taught me to mind my business but just for this time I will please you...".