Other members of the New Kids - Donnie Wahlberg, Joe McIntyre, Jordan Knight and Danny Wood - believe their young fans want them to be unattached romantically, and Jonathan and Tiffany have been sternly warned to end their heavy relationship before it wrecks his golden career.

The fans like their New Kid heroes young - and available!

"Jon is miserable since his people told him to cut Tiffany out of his life," an insider told The GLOBE. "He's really in love, and now he's being told to stop seeing her or risk losing everything he's worked for.

"But his fellow band members told him if he continued with the romance, his career could be over - as well as Tiffany's and the rest of the New Kids. He was told his romance with Tiffany would get too much publicity and fans would turn their backs on him if they knew he was really in love.

"The people who manage him have told him the same thing, but he won't listen."

Tiffany was given the same lecture by her advisers, and she has taken the advice much better than Jon.

"They told her to stop seeing Jon for a little while just to give the media guys a rest," says the insider. "She understood perfectly well that she was leading her career into hot water.

"Tiffany is only 19, but she's a really mature girl, and she knows how delicate these things can get.

"She promised she'd cool it for a while and would just call Jon on the telephone until all the attention on them fades. She understands that her fans, as well as Jon's, are hurt and disappointed when someone they like in a group gets seriously involved in a steamy romance.

"It's not good for business, especially when things are going so well for Tiffany and Jon."

But Jon, 21, balked and has refused to end the romance, which has been sizzling behind the scenes since last summer.

"I love Tiffany a hell of a lot more than I do the New Kids on the Block," he told pals. "I don't want to break from the group, but I will if they don't leave me and Tiffany alone.

"All Tiffany and I want to do is be together. We're not hurting anyone. We're just dating. I don't see why they're making such a big thing of it," he said, "even if we are in love."

Jon and Tiffany have publicly denied the romance, but another source says: "Jon won't accept the possibility that if he tells everyone he's in love, his young fans are going to turn their backs on him forever.

"He has become real moody about it. He's stubborn. No one wants to see him lose everything, but the way that boy is going, it may not be long before the love bug puts him right in the poorhouse. The skyrocket ride to stardom by the New Kids on the Block may all fizzle out because of love."