not ever "gay" man does. but 99% do. i figure some gay men that lack this smile are purely pitchers and not catchers. i think its the same thing with women. everyone frowns. people will frown when they are going through pain. but i think that the mouth muscles change over time due to exposer to constant pain.  im sure theres some studies out there that could back up my claims. but its just an observation. i bet if they had facial recognition do all gay men faces on the internet a majority of the smiles would look like this.
United States