I've always hated the word "widower," as that sounds like someone who MADE someone a widow, either by dying, or by killing her husband. Like SirHugs, I prefer using the term widow for a man or a woman who has lost their spouse to the Grim Reaper.
As for the story, the "Mr. Mom" concept is a familiar one, and has lots of potential. For example, since most of the moms are women, they are accustomed to bitching about their husbands to each other. And our protagonist learns all the things that they are NOT getting..... and he knows just how to supply them......