Shameless Remake.
It's not mentioned in Movie Connections, but this is an obvious remake of Australian film "Strange Bedfellows" (2004) - see http://www.imdb.com/title/tt0360032/. That film starred Paul Hogan and Michael Caton and the IMDB describes the plot as...
"Two 'very straight' old timers have to learn how to pass as a loving gay couple after falsely claiming same-sex status to take advantage of newly legislated tax laws."
...whereas THIS film's plot is...
"Two straight, single Brooklyn firefighters pretend to be a gay couple in order to receive domestic partner benefits."
Golly - WHAT A COINCIDENCE!
Laura Ess