I now pronounce you Chuck & Larry - review
The drive of the film centres around the voyage of discovery (which is driven home in the 3rd act) whereby the guys actually begin to experience prejudice whilst living fraudulently as a gay couple. Realizing that this is once the way they viewed and treated gay people, they vow to change their ways and attempt to enlighten others.
Running concurrently with this message of tolerance, there are some great gags and some predictably juvenile humour.