the story of gaylord focker
Pam (a.k.a. Pamela Byrnes) and Greg (a.k.a. Gaylord Focker) like each other. Greg is on the verge of proposing to Pam, and has even made a diamond ring. Now Pam has a dad whose approval she needs before marriage. So she brings Greg along to her house for the week.
Things start to get in motion right from the airport. Greg's bag is mishandled and probably lost by the airlines company, which is why he arrives at her parents' house empty-handed. He doesn't have his tooth-brush, he doesn't have his clothes, and by the end of the week, he doesn't have the important thing for which he has come to her house – her father's approval.
In a series of mishaps and mumbo-jumbos, even the wedding of Pam's sister is seemingly ruined by Greg; and hence the anger of the entire Byrneses, especially that of the big Mr. Jack Byrnes, a walking, talking, stalky lie-detector and a former CIA agent. A miserable Gaylord Focker thus walks out.
What happens next is your guess, unless you watch Meet the Parents and Meet the Fockers.