From IMDB (http://www.imdb.com/title/tt0109831/quotes):
Gareth: I've got a new theory about marriage. Two people are in love, they live together, and then suddenly one day, they run out of conversation. Charles: Uh-huh. Gareth: Totally. I mean they can't think of a single thing to say to each other. That's it: panic! Then suddenly it-it occurs to the chap that there is a way out of the deadlock. Charles: Which is? Gareth: He'll ask her to marry him. Charles: Brilliant! Brilliant! Gareth: Suddenly they've got something to talk about for the rest of their lives. Charles: Basically you're saying marriage is just a way of getting out of an embarrassing pause in conversation. Gareth: The definitive icebreaker.
no subject
Gareth: I've got a new theory about marriage. Two people are in love, they live together, and then suddenly one day, they run out of conversation.
Charles: Uh-huh.
Gareth: Totally. I mean they can't think of a single thing to say to each other. That's it: panic! Then suddenly it-it occurs to the chap that there is a way out of the deadlock.
Charles: Which is?
Gareth: He'll ask her to marry him.
Charles: Brilliant! Brilliant!
Gareth: Suddenly they've got something to talk about for the rest of their lives.
Charles: Basically you're saying marriage is just a way of getting out of an embarrassing pause in conversation.
Gareth: The definitive icebreaker.
Is that what you were thinking of?