Wow, this thread is ancient! Anyway, some definitions. A traditional cuckold does not know his wife cheats on him; he is held in low regard by society for being unable to control his property. A modern 'cuck' fetishist is a wittol, a willing wimp, a kink gaining him victim status if he's humiliated, or who just likes to watch.
I've only written one fetishistic 'cuck' tale, Double Your Fun in LW. In most of my stories, the cheated husband never finds out; or he exacts revenge; or there are polyamory groups. Wittols seem almost abstract to me.