It's Always Sunny in Philadelphia Season 6 Episode 1
Mac Fights Gay Marriage
When Mac learns his transvestite ex-girlfriend has completed her operation and marries another man, he fights gay marriage!
Meanwhile, Dennis finds a way to relate the situation to himself... why isn't he married yet? Dennis calls his old high school sweetheart and marries her on a whim.
When Charlie injures his back, he and Frank decide to get gay married for the insurance benefits. Turns out neither has to have their dick cut off and sold to China.
Sweet Dee ends up sleeping with her married high school crush, Bill Ponderosa, brother of Dennis' now wife, Maureen.