Right up to the wedding of Monaco's 21-year-old Princess Caroline and her discotheque-hopping fiance, Phillippe Junot, 38, guests were still asking each other what the bridegroom really does for a living.

"He says he's an investment banker, but he's got no money - and no bank," said a friend of Caroline's mother, Princess Grace.

The official press release of the principality of Monaco describes him, however, as "a financial and investment adviser to international banking establishments" with "offices in Paris and Montreal."

A story last week in France's largest circulation daily newspaper, "France Soir," repeated widespread Paris talk that Junot's money comes in fact from Saudi Arabian jet-setting mogul Adnan Khashoggi. In Monaco, officials said that the paper was getting a letter from Junot's lawyer denying any financial link between the two men.

Such apparently dubious stories get widespread attention because of the mystery surrounding Junot's business affairs.

If Junot himself seems undisturbed in such talk, he is equally blase about his persistent reputation as a playboy. Junot and Caroline spent much of their courtship going out together to the trendiest discos in Paris.

Junot dismisses the word playboy. I am just someone," he recently told an Italian interviewer, "who wants to have a good time like anyone else. The difference between me and other people is that I manage to do it. I work a lot. But when I'm finished, I play tennis, I go out to dinner with fun friends, I go dancing . . . I go to sleep at 4 or 5 in the morning, and at 8:30 a.m. at the latest, I'm awake and ready to start my day."

Junot's father, Michel, one of the deputy mayors of Paris, has also been denying his son's reputation as someone who is not, as the French say, "serieux." "Look, my son is respectable," Junots pere recently told an acquaintance. To prove his point, he produced a piece of his son's official-looking letterhead stationary.

For the Junots, the wedding celebration was a real family get-together. At the Hotel de Paris, Philippe Junot's mother and stepmother sat side by side, along with his father, at a lavish dinner preceding Tuesday night's grand ball at the palace.

They were not the only "exes" around. Designer Diana von Furstenberg was escorted by her former husband, Prince Egon von Furstenberg.

At the Grimaldi household, Prince Rainier and Princess Grace have been stressing that the wedding of their elder daughter was to be an intimate family after rather than an official state occasion. They were so adamant that they had their spokesman repeat to anyone who would listen that Princess Grace herself is still traumatized by the memory of her own media-circus wedding to Prince Rainier in 1956.

"She still speaks of her marriage as the worst event of her life," said Jacques Sallebert, head of Tele-Monte Carlo, the principality's capital television station.

"Grace has an awful memory of her wedding," said Sallebert. "Her marriage was invaded by photographers and TV cameramen who pushed her around. Princess Grace really panicked the day of her marriage. She was determined not to let that happen to her daughter."

Of course, Sallebert said, the family realizes there must be a grand state ceremonial when Caroline's younger brother, Prince Albert, the heir to the throne, is married.

"They're saving the pomp for the prince," said Sallebert, in explanation of the restrained use of external signs of celebration in Monaco this week.

This explanation was apparently also intended to dispel persistent suggestions that the family's insistence on an "intimate" marriage, preserving as much privacy as possible for a reigning family, reflected any disapproval of the match.

Sallebert, who was for years the chief correspondent for French state radio and TV in New York, said that he had to argue very hard to get Grace even to permit a microphone in the palace's Throne Room to pick up the couple's "I dos" at yesterday's civil ceremony. Asked whether another microphone would be in front of the throne to record what he called the grand moment when Rainier, as chief of the house of Grimaldi, was to give his assent before the marriage could proceed, even Sallebert recoiled in horror. "You can't be serious," he replied. "You can't have a microphone in front of the throne."

Sallebert had obviously been rehearsing what he was saying about the marriage. He began an interview in his office as director of Tele-Monte Carlo, where a television tuned into the station provided constant background noise by emphasizing the official view that this was "a family affair, not an affair of state," and recalled Grace's terrible memories. When the evening news flashed on, there was Sallebert on screen stating word for word that he had said moments before in the interview.

Sallebert gave no sign of embarrassment. "Lovely pictures, aren't they?" he asked as stock aerial shots of the principality and scenes from Caroline's engagement announcement appeared, with him narrating.

Nadia Locoste, Monaco's chief press officer, was answering questions in the press center facing the Place duCasino. Her soft boffant hairdo was not unlike the gentle waves worn by Princess Grace in a photograph hanging behind Lacoste. She said she was deluged by more than 250 reporters and photographers from around the world. By week's end, she expected more than 400.

"And that doesn't count the five writers and three photographers from the National Enquirer." said Lacoste. "They've been here for 10 days." Lacoset suggested that the Enquirer people have been trying to buy bona fide invitations to the event, which is closed to the press. "They're only looking for the negative side," she said.

Not all the media was so eager. NBC, for example, did not even plan to send a team to Monaco until Newsweek put Caroline on the cover of a recent issue on "The New Royal Wife," NBC rapidly dispatched a full team to turn out several stories a day.

Not to be outdone, NBC-TV pressed media veteran Pierre Salinger into service. CBS beefed up its regular Paris team with the familiar face of Hughes Rudd.

Yet Newsweek itself didn't bother to send anyone to Monaco this week. "We've already done our piece," said a Newsweek staffer in Paris. Time magazine, which has not had Princess Caroline on its cover for three years, sent its Paris bureau chief.

Lacoste said the wedding was mainly an attraction for the English, American and German press. "Even the local daily, Nice-Matin, which runs a daily Monaco edition, has not been giving the wedding especially heavy coverage. The French are used to Caroline," Lacoste said. "For them it's mainly a picture story." The press, Lacoste explained, came to Monaco not to report what was actually going on here, but to write "what they had decided they were going to write anyway before they left."

One American author of a recent Sunday magazine article that the palace regarded as unflattering, said he was now being frozen out.

"I don't understand," said Lacoste," why anyone would write that kind of thing. For most people, Monaco is a fairyland with a prince and a princess. It's a land of hope and sunshine. It's so nice to know that a princess can marry a commoner," Lacoste said. "Caroline could have married a king. It's like becoming president of the United States. It can happen to any boy or girl. Fairytale things can happen and peopld want that image of Monaco. In this world that's so drab, so full of violence, Manaco is like a Christmas tree. So let's see it all trimmed."