Searching for an episode

[captawb]

I'm making a disc of all my favorite whose line moments, and I need some help finding a certain scene from the American version. There's one scene from a game of SFAH where Colin and Ryan are walking down the aisle at their wedding. Colin gets diarrhea or his water breaks or something, screams Oh, then he & Ryan look each other in the eyes and slowly kiss.

Does anyone know what episode that's from?