This sounds exactly like the 2004 Australian film "Strange Bedfellows" starring Paul Hogan. Compare the IMDB synsopsis -
Chuck & Larry: Two straight, single Philadelphia firefighters (Sandler, James) pretend to be a gay couple in order to receive domestic partner benefits.
Bedfellows: Two 'very straight' old timers (Hogan and Caton) have to learn how to pass as a loving gay couple after falsely claiming same-sex status to take advantage of newly leglislated tax laws.
I Now Pronounce You Chuck and Larry - Um, seriously?
AfterElton's Best.Gay.Day.Ever blog has some commentary about this upcoming "faux gay firemen" comedy starring Adam Sandler and Kevin James.
"...it is the weak who are cruel, and...gentleness is only to be expected from the strong." - Leo Reston
"Cruelty might be very human, and it might be cultural, but it's not acceptable." - Jodie Foster
"Cruelty might be very human, and it might be cultural, but it's not acceptable." - Jodie Foster