There is nothing wrong about it as long as it is not one of a marital offence. It is just some source of where the guy derives fun which of course the wife may as well have Source by which she feels fun especially when the husband is not around.

I don't see gambling being an issue to a responsible married man as far as he is also doing the gambling stuffs in the responsible manner. So he can go ahead and tell the wife but should not make the wife feel that the bedtimes with Hera's claimed was not necessary or remarkable.

The wife on her own may even tend to also tell the husband probably that she enjoys doing the house chores especially dealing on the delicacies in a quiet time when alone.
So it does not make any offence of couple telling each other how they finds fun at their leisures.