From PEOPLE Magazine Click to enlarge
Is it something in the drinking water? Consider this recent spate of unlikely celebrity pairings: Barbra Streisand and Don Johnson, Rob Lowe and Fawn Hall, Sylvester Stallone and Cornelia Guest (who, despite ugly rumors to the contrary, are still dating). Curious couples indeed, yet they're overshadowed, figuratively and literally, by the pairing of those perfect physical (and fiscal) specimens Brigitte Nielsen, 24, the ex-Mrs. Stallone, and her fiancé, the not-quite-divorced New York Jets defensive end Mark Gastineau, 31. No matter that the calendar says it's only April Fool's Day—Gitte and Gastineau are the oddest couple of the year.

The scene: a quiet country road in Denmark, about 40 miles from Copenhagen. A pair of humongous lovebirds comes flitting down the path, unable to keep their hands or lips off each other. She's a Viking's dream—140 lbs., 6' tall. He's a quarterback's nightmare—265 lbs., 6'5", a full seven inches taller than Sly, a man Gitte can, at last, look up to.

After visiting Gastineau's parents in Scottsdale, Ariz., the hard-bodied twosome had dropped in on Munkerup, home of Nielsen's folks. Mark has been getting acquainted with father Svend, an engineer, mother Hanne, a librarian, and Julian, Brigitte's 4-year-old son from her first marriage to Danish musician Kasper Winding, who lives nearby. Obviously this is no flesh-(sorry, flash-) in-the-pan romance. Nielsen and Gastineau have been together for nearly two whole months—or, as Gitte told a reporter, "two wonderful months. We're both madly in love."

No argument from Gastineau. "I believe there are only a few people in this world who know Brigitte as she really is," he said. "I love her deeply, and if anyone should ever try to hurt her, I'll Kill them." Not exactly a Shakespearean sonnet, but it will do.

Of course the skeptical might say that the love affairs between Gastineau and Gastineau and between Nielsen and Nielsen are already two of the more ardent liaisons of the century. One of the NFL's more flamboyant players, known for his grandstanding postsack dances, nine-year veteran Gastineau rarely passes up an opportunity to draw attention to himself. As for Nielsen, an aversion to seeing her name and body in print is not one of her faults. Since coming to the U.S. three years ago, she's gone for everything but broke, copping roles in Cobra, Rocky IV and Beverly Hills Cop II as well as a reported $6 million settlement when her 18-month marriage to Stallone was KO'd last July.

"They're cut from the same mold, both publicity conscious," says Gastineau's wife, Lisa, 28, who's suing for divorce on grounds of cruelty. "He lives for that."

While Lisa claims she isn't envious ("This rivalry business is bull. I'm way past that"), she's "really surprised" that Mark and Brigitte are together. "I can't figure it out, because he's a very jealous type," she says, sitting in the living room of the Huntington, N.Y., home she once shared with Gastineau. "I can't see him with any person who has a past—and God, she has a past! He married me when I was 19, and he was jealous of boys I went out with when I was 17. If I was in the gym or the pizza parlor, he was obsessed with who I talked to. God forbid they would be good-looking. He wouldn't let me wear certain clothes, certain bathing suits, because they were too flashy. Anybody who knew us knew how jealous he was."

Gitte, however, has a slightly different reading on Gastineau's character. "He's incredibly sweet," she told the reporter. "He's a quiet and shy guy—when he's out of the spotlight."

Gastineau was highly illuminated when Nielsen first saw him last November. Specifically, he was on TV, giving a postgame locker-room interview clad in nothing but a towel. Taking a shine to what she saw, Brigitte—in accepted nouveau Hollywood fashion—soon had her people calling his. (The way she first saw Mark, interestingly, was an odd reversal of the way she had met Stallone: by sending her photos up to his New York hotel room.) "I never believed I'd fall in love again so quickly," she says. "I'd just bought a new home, and the thought of a new man really didn't have much place in my mind."

Since her split from Stallone, Nielsen had been leading a typically low-key life—hosting a variety show, Festival, on Italian TV, then returning to party in L.A. clubs and posing for two new posters.

Mark and Brigitte finally met at the Super Bowl but don't recall when they actually started dating. "I can't remember the exact date," says Nielsen. "Can you, Mark?"

"No," he says. "The days really have flown."

Soon-to-be-ex-wife Lisa can remember: It was in early February. "He called me up the first week in February and said, 'Can you keep a secret?' Mark's like a kid; he likes to impress me. He has a hard time; I don't impress easily. I know he was busting to tell me his secret, so I said, 'No.' He said he'd tell me anyway. He said Brigitte had been pursuing him through his agent and he didn't know what to make of it. He said they'd met at the Super Bowl, and now she was calling, wanting him to come back to California, even offering him a car to drive."

If the lovers don't know when they met, they know where: in an L.A. gym. Mark, no mean specimen (he was once considered for the Dolph Lundgren part in Rocky IV), made a suitable impression on Brigitte. "When we met in the gym," she says, "it just said bang for both of us."

It's been impossible to pry them apart ever since. Dividing their time between her West L.A. home and his Atlantic Beach, N.Y., condo, they hit the gyms by day and the boîtes by night, displaying their hickeyed necks, for example, while announcing their betrothal to a cheering crowd in Don Pepe's, a Queens, N.Y., Italian restaurant. During all their travels, Mark and Gitte have acted like, hey, a really fun couple. Paying a visit to Manhattan's Cafe Society one evening, Gastineau reportedly carried Nielsen around on his shoulder while she removed her blouse (a camisole was underneath). They ended up on the floor, rolling in passionate embrace.

Maybe you had to be there, but the ecstasy hasn't been universal. According to Lisa, the Gastineaus' daughter, Brittny, feels slighted by the love games. Brittny, 5, recently returned from spending a week in California with Mark and Brigitte. "She felt so left out of his life," says Lisa. "She was traumatized. She said, 'My daddy doesn't love me—he loves Brigitte.' "

No such problems can be found in Denmark, according to Gitte. "My entire family is just crazy about Mark," she said to the reporter. "He's completely charmed his way into their hearts. He and Julian get along perfectly; they've been playing with the new go-cart we bought for him. And my parents are overjoyed because they can see I've never been happier in my life. That's why Mark and I are going to get married. The exact date hasn't been set yet, but this year."

Which comes as news to Lisa. "We're still not close to divorce," she says, "not unless he comes up with a settlement tomorrow. And he's not one to part with a dollar too quickly."

In any case, Nielsen has Gastineau's number, in every sense of the word. Soon after they started dating, Gastineau, whose football jersey number is 99, gave Nielsen a note. "It said that after meeting me he was only number 9," says Brigitte. "The other 9 hereafter belonged to me, and he had bought us both a 9 digit in solid gold. I almost burst into tears."

Ain't love grand? Well, Stallone's outspoken mama thinks it can be grand larceny. "Gitte is the poorest example of a female I've ever known," says Jackie Stallone, holding court in her L.A. home. Jackie has never been known to give Nielsen high ratings, but she does have some parting advice for Gastineau. "That football player—I wish him luck. I just hope he's not silly enough to put his income in a joint account with hers."

—By Joanne Kaufman, with Jorgen Salomonsen in Copenhagen and Alan Richman in New York