The trouble with going on a taxpayer-financed trip abroad is that you can't afford to say you had fun.

Members of the official U.S. delegation to last week's meeting of the Interparliamentary Union in Lisbon described the 12-day trip as "interesting, informative, constructive, educational and useful," but not fun.

Rep. J. J. (Jake) Pickle (D-Tex.) came as close to owning up to a good time as anyone, saying "sure, I enjoyed it." Pickle said he takes "pleasure and pride" in mixing with fellow legislators from 75 other nations at the semi-annual IPU conferences.

Several members of the 14-member congressional delegation agreed with Rep. Edward J. Derwinski (R-Ill.), however, who said the staff that accompanied the delegates was "larger than necessary."

In addition to four senators, 10 congressmen and their wives, the party included five military escorts, 11 congressional staff aides and three of their aides, and a crew of 22 that went with the Air Forca plane that took the group to Lisbon, via London, Paris and Geneva.

A couple of the representatives also said privately that the side trips to England, France and Switzerland were, in the words of one, "a bit excessive," although Pickle said the "most interesting" event of the 12-day trip occurred in Geneva.

Pickle cited an exchange between Sen. William L. Scott (R.-Va.) and Paul Warnke, the U.S. ambassadr to the Strategic Arms Limitation Talks.

"Scott really let him have it," Pickle said. "He told Ambassador Warnke 'you should never have been confirmed.' That sure did wake all of us up," said Pickle, who added that Warnke "managed to keep smiling through the whole thing, although his eyes glistened a little."

Pickle said Scott "took on Warnke in his typical blunt manner," telling the SALT negotiator that "the reason we have 40 votes against you in the Senate" is his failure to insist on inspection of Russian weapons onsite.

Scott said in an interview in Lisbon last week that he "used to crude parallel" in his walk with Warnke to emphasize his contention that counting the number of missile launching locations is not an adequate safeguard "because it's entirely different if you view single-shot rifles and machine guns as equals."

Rep. Lionel van Deerlin (D-Calif.) was among several delegates who said the two major accomplishments of the IPU conference involved defeating anti-American resolutions on the neutron bomb and how to deal with terrorism.

Rep. M. Caldwell Butler (R-Va.) expressed a common justification for U.S. participation in the conference, saying, "I don't know how we could avoid it." Most of the delegates fear that if America were not present, the conference would churn out a series of anti-U.S. resolutions.

Rep. Richardson Preyer (D-N.C.), Butler and van Deerlin all said a highlight of their Lisbon visit was the one-hour meeting with Portugese Prime Minister Mario Soares.

They praised the Socialist leader of "the only country to ever turn away from a Communist government in favor of democracy," as van Deerlin put it, and said they were impressed with his desire for cooperation with the U.S.

Rep. Joseph L. Fisher (D-Va.) said rubbing elbows with legislators from other nations help Congressman from being so "insular," but the U.S. group was so pampered by military escorts, embassy attaches and aides they brought along from Washington that they had few opportunities to meet ordinary Portuguese people.

From the windows of their chauffeur-driven cars, however, they could see, smell and hear the symbols of the peaceful revolution that ended the autocratic regime of Antonio Salazar on April 25, 1974.

Posters and graffiti adorn nearly every public building in Lisbon. Street-corner vendors sell red carnations, a reminder of the revolutionary poster of a soldier with a carnation sticking out of the barrel of his rifle.

Drivers celebrate their new freedom by honking horns without provocation, and pedestrians spit with reckless abandon.

"Under Salazar," explained a taxi driver, "you could go to prison for spitting on the street. So now we spit on the memory of Salazar, we spit for freedom."