The gender pay gap is the myth that just won't die. It fails to make the basic distinction between earnings and wages.
But whatever, if it's voluntary, I guess guys can go there in order to win brownie points with women who like to believe they are victim of the big bad evil patriarchy.
Great idea :) And I think to make it even more fair, that kind of cafe will need to make 18% bigger burgers for those guys who pay 18% more!
ヽ(。_°)ノ