Brennan Hough, a 39-year-old homebody, and Dale Doback, a 40-year-old layabout, are unexpectedly brothers. The single parents, who have been providing full board for their children all their lives, decide to seal their union after a fateful meeting at a conference.
The newly-minted family gathers under one roof with one bedroom for their sons. Naturally, this arrangement does not suit the spoiled "boys" and they begin to hate each other with a fierce hatred. But suddenly they find out that they don't have so many differences. That, like 12-year-olds, they are trapped in adult bodies.
And then, just as an unlikely friendship begins to bond them together, their parents decide to divorce. Will anyone be able to separate the brothers now? Or will they take anyone out on their own?