Jerry is sending his parents Helen and Morty to Paris for their anniversary, but he counts the days until they leave and he can finally have his girlfriend Rachel over after weeks apart. George gets recruited as a Big Brother mentor to young Joey. George decides to fake his own Paris trip to get out of this, and ropes in Jerry's parents to mail postcards from Paris in his name.
Kramer is wearing used vintage clothes from Rudy's, sold off when their former owners passed on—reminding George of his father Frank's old clothes in the attic. George invites Jerry's parents to dinner with his parents, but they are noncommittal. Jerry is surprised by his parents confiding that they have never liked the deranged Costanzas.
Elaine's boyfriend Aaron, an uncomfortably "close talker", meets Morty and Helen. Aaron immediately offers franc bills for their trip, then whisks them away to the Metropolitan Museum of Art for a day-long behind-the-scenes tour. Elaine and Jerry are confused by Aaron's devotion to two total strangers.
Morty recognizes Kramer's beltless raincoat as his own poorly selling design, the "Executive". Kramer promises to offload Morty's unsold stock at Rudy's for a finder's fee. However, Morty needs Jack Klompus's help to ship the raincoats to New York before the Paris trip. George's excuse backfires, because Joey happens to need a travel companion to reunite with his father in Paris. George fails to pawn Joey off on the Seinfelds.
The Costanzas haplessly wait two nights for the Seinfelds, Estelle having made too much paella. George steals into the attic in the night, making Frank jumpy that mice have gotten in. Selling Frank's clothes to Rudy, George gets an extra $25 by tearfully eulogizing his "late" father. George finds out the Seinfelds had dinner with Kramer, and becomes indignant on his parents' behalf for the snub. Rudy sells Frank's shirts to Kramer, and is keen to buy Morty's raincoats.
To Elaine's dismay, Aaron enjoyed the Seinfelds' company so much that he brings them along to see My Fair Lady with Elaine, followed by dinner and even a romantic carriage ride. This outing gives Jerry and Rachel some alone time, but not nearly enough. Meanwhile, Jack fails to unlock the Seinfelds' garage to retrieve the raincoats.
George shares in his parents' outrage at being snubbed twice. Frank and Estelle move on to planning a cruise, but Frank complains that he needs his missing "cabana wear" from the attic. Meanwhile, Rudy burns Frank's clothes to purge a moth infestation.
At Helen's recommendation, Jerry and Rachel go see Schindler's List, but they cannot resist making out through the solemn movie. Kramer and Morty both arrogantly demand a bigger cut of their take, only to split the difference and end up back where they started. George refunds Rudy for the moth infestation, but learns too late that the clothes are gone.
Newman, who saw Jerry and Rachel's indiscretion, gleefully tattles to Helen and Morty, who reprimand Jerry. Jack calls to report that he not only smashed a window to get the raincoats, but also cheaped out on shipping, cutting the delivery too close. Morty chooses the raincoats over the Paris trip because he "can't stop now".
George invites Kramer over to finish off the paella, but Frank recognizes his cabana shirt on Kramer. George blurts out having sold the clothes to Rudy. He also takes the Seinfelds' forfeited plane tickets for himself and Joey. At the airport, Morty finds the raincoats strewn about because Jack did not tape the box, while George suffers Joey's disrespect.
Back at Rudy's, Frank learns that his "death" netted George $25. Thanks to Frank's moths, Rudy stops buying secondhand clothes, leaving Morty and Kramer holding the bag. Aaron is even more sentimental than Jerry as they see Morty and Helen off back home; guilt-stricken, he laments that he "could have done more" for them at even greater personal expense. Jerry is forbidden from seeing Rachel again after Newman, as postman for Rachel's household, tattled to her morally righteous father. Jerry finds Newman and vengefully chases him.
Morty and Helen return to find the house robbed clean through the broken window. They seek respite on a cruise, but get booked on the same ship as the Costanzas.