I never thought of a gas mask as something very interesting before. But I really do like the idea of it being part of an end of the world role playing plan. This photo was really nice too, a little tender and strong too.
To me the man in the photo could be anything: Dom, sub or just a regular guy with no D/s at all. There they are, the survivors, looking for a way out of the rubble. Maybe a farm out of the city where they can find a few surviving animals and grow their own food. Likely they'll find some clothes along the way.
Someone could write an interesting FemDom story in that kind of setting. There would be a lot of work, they'd be pretty alone and all the gas masks would be free.
